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·MOSQUITO REDUCTION AND MALARIAL PREVENTION

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·MOSQUITO
Reduction and
MALARIAL
Prevention
A PRECIS
BY
JA CRAWFORD
AND
BS CHALAM
OIFORD UNIVERSITY FRESS
LONDON NEW YORK BOMBAY
CALCUTTA MADRAS
1926

·All rights nese) ed Px NTED AT FE WESLEYAN M SSION PR SS BISSORE CI —1976

·Tuis Book is DPDICATED
TO
LT COLONCLS R CHRISTOPHERS FRS CUF OBE IV

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·sonENORD
Tur Authors of this mall book are quite
correct when they point out the need of a work
such as they nos put forward Vany books it is
true deil with inti malarial work and many with
various aspects of the study of malaria entomo
logical parasitological clinical etc
There are
also general treatnes on maltra and works on the
practical prevention of the disease But the inct
remity that is very difficult to recommend a
book to beginner that will give him the simple
facts and interests be requires to help him in
commencing actual practical work in the field
The Authors hoe met the needs of a manager
of 1 fed guden or a molarııl inspector or the
NCO in charge of a regimental stary squad
from their own experience of what such persons
require The gre n briei bor sufficient account
of the nature of malarial fever of the chret facts
about mosquitoes and of how to find and identity
mosquitoes especially the Indian species of malaria
Crices They end with an account in some
detul of practical steps to be taken in prevention
ind in the form of appendices, with some helpful

·V111
FORETORD
notes on the technique connected with mounting
and preserving specimens
The Authors them
selves have had the practical experience that
qualifies them to write helpfully for others and I
wish their venture every success
SR CHRISTOPHERS

·PREFACE
THE Authors in placing before the public
this volume do so with the hope of filling i need
long felt by the worker and inspector in anti
malarial measures There are at present many
tomes and excellent treatises dealing exhaustively
with the life habits and elimination of mosquitoes
and many are written with a view to controlling
yellow fever and malaria—but the man who is
too busy in other walks of lile or who has not
the necessary technical education cannot readily
acquire the knowledge contained in these We
have only introduced such technical names and
phrasing in this book is ire absolutely necessary
for the proper understanding of the subject and
*here these are introduced the are explained as
simply as possible It has been our experience
that the miniger of a tez garden or a maları
inspector or the NCO in charge of 7 sanitary
squad derling with antı malarial measures begins
to take 1 much heener interest in his work when
he has acquired some knowledge of the habits
and life history of the mosquito and it is primarily
in the hope of quickening their interest that this
work has been undertaken

·PREFACE
his miny
Our thanks are due to Lt Colonel S R Chris
tophers Fus CIE OBE I MS for his
kindness in reading through our work and for
valunble criticisms and also for
allowing us to include a Synoptic Table o
Indian Anophelını issued
issued by the Central
Malarnal Bureru kaszuli 1926 We also desire
to thank all who by their kind criticism have en
couraged us in our work
BOMBAY
JAC
June 1926
BSC

·CONTENTS
PACE
FOREWORD
1x
PREFACF
CHAPTER 1
TIIA Cactors Calsing MALARIA
1
CHAPTER 11
Liff HISTORI OP MOSQUITOFS (FrG LARVA
PUPA)
9
CHAPTER 111
THF ADULT Mosquito or Iaco
70
CHAPTER 11
111E HABITS or MOSQUITOPS
38
CHAPTER 1
I RFI TNTNF \l Orx
57
85
API CVDIVIS
100
IND

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·LIST OF ILLUSTRATIONS PAGE DESCRIPTIVE DIAGKAN ANOPHELES (Female) frontispiece LIFF CICLE OF THE PLASMODIUM (Oppostle) 6 The O\UX Ox Ecc 11 PALVATF HAIRS 16 THE LARS 17 POSITION OF LARVAR OP AAOPTELIVI AND LILPY IN WATEX 18 TIF Pura 91 VARIETIES OP SCALES HEAD SCALPS or STFGONYA AND CILEX 33 hel SHORF AT COLABA BOSIBAY (UPA sile) 4° VARINE GROWTII STARCMSG A POOL FOR I ARVAE ol SPR4178C POOLS 61 A WILL WITH CENEYT LOVE 73 A MOSQUITO I ROOF TANK 73

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·CHAPTIRI THE FACTORS CALSIN YALARIA VI ILIKI4 is probably the commonest disease that affects minkind and its ranges zre spread over large reis of the world Nor is it 1 discase of comparatively recent origin for we find reference to it in the writings of ancient Greece and Rome Ith ranges art evidenced in manifold directions for not onls does it in certain instances destroy the life of the individual infected but also from its chronic nature, debilitates him and thus exposes the un fortunate person in tricks of other and more gmie disorders In Indın alone it is estimated that come four millions of people applı annually for treatment for multi and there must be many others who do not apply for treatment add to that number the vant army of sufferers outside Indin we shall have some ider of the widcapread character of this disen e The economic and financial loss which arises 15 1 direct and indirect result of the ravages of mulari can only be touched upon here Vliny a dry labour is lost to those who employ people suffering from this disease and the employees themselves broken in health by recurring bouts If we ·2 MALARIA of fever cannot be productive of the same amount or of as high a quality of work whether mental or physical as those who labour under conditions where malzria does not exist I he financial loss to the employers of labour in malarious districts is immense and in this direction one cannot but refer the reader to the literature dealing with the subject If this disease were to be eliminated the gain to mankind from a humanitarıın and economic stand point would be beyond belief and it is from this point of view that we must approach the subject We must first of all try to discover what essential factors are necessary to bring about this disease and where if possible we can break in upon and destroy either all or one of these factors As we have already mentioned this disease is to be found described by the ancient Greek and Latin authors and even in those days the relation ship betseen marshes and malına sas recognized In the middle ages a type of mosquito net was mentioned as the only safeguard to those living near marshes This would seem to correlate for the first time fever marshes and insects The next real advance made was the discovers of Cinchona By its use the physicians in the eighteenth century were able to distinguish between those fevers which reacted to Cinchona (1 e quinine) and those that did not ·MAI ARIA 3 $ The name Malaria is derived from two Italian words 'Mal and Arii meaning bad air ind refers to the belief that the cause of the condition was due to bad air arising from marshes It was not however until 1881 that the really first big step was made in solving the problem of its cause In that year the I rench suręcon Laieran demonstrated that malaria was caused by a minute organism which attached the blood corpuscles Following quickly upon thi the Morkers in the subject established three distinct organisms which caused three distinct types of fever These organisms ir called fla modum in which cruscs Benign turtuin mi laria Plasmodium malariat which cruses Quartan mrlaria and Plasmodium falciparum which causes Malignant malaria Up to this time we had two of the three great factors in this diserse-namely min and the plasmodum Having found that maların 475 caused by these orginisms it yet remained to be discovered how man became infected or how the disease spread and it 478 not until 1895 that Sır Ronald Ross sorhing on a hypothesis put forward by Manson demonstrated that mosquitoes spread the disease from man to man by their bites Thus were the three great factors man mosquito and plasmodium linked up and the cause and method of spread of malaria definitels settled ·VALARIA In order that we may arrive at 1 full com prehension of the manner in which these three factors are linked together we must have a knowledge of how the plasmodia infect man We will consider the plasmodium itself This organism comes very low in the scale of animal life seeing that it consists of one cell only It is classed as a Protozoon The substance called protoplasm of which this unicellular organ ism is composed has the same properties as hrve cells used in building up the tissues of higher animals that is to say it grows moves assimi lates food and reproduces itself by division Its reproduction is of two distinct types asexual and sexual It also has the power of producing a variety of chemical substances The organism itself has a nucleus situated in the midst of pro toplasm which is the substance of which all living cells are built up In its methods of living it is entirely parasıtıcal that is to say it lives at the expense of other animals which are called its hosts Like all true parasites the plasmodia must adapt themselves to life inside their hosts and must be able in order that the species may be muntained to pass from one host to another Thus it is that the parisites grou and multiply by one method in one host-man-and by another method in mosquitoes The former is called the ·VALARIA > 74exual life and the latter the sexual life of the plasmodium The three species of malarial parasites the Plasmod Iar Plaon odım malarial and Pla modum falufarum produce three distinct types of fever These are the Benign tertian Quartin ind Valignant fevers The sexual forms of the Qurrtin and Benign tertian--that is to say those adapted for life and des elopment in the mosquito-Tre spheru al This form of Valignant tertuin is crescentic There are male and female spherical forms and male and female crescentic forms The male cerul formy fertilize the fenal forms in the stomach of the mosquito and 1 Cynt 15 produced which imbeds itself in the wall of the stomach any such cists are formed there ind these appear in the walls of the stomach like rains in 7 pudding The contents of the Cits divide and form spores or young parasites which find their way to the salary glands of the mo quito This whole process which con stitute the sexual life of the parasite in the mosquto tikes about twelve days to complete Tou the mosquito is rends to infect the other host Suppo e sht bites then down the proboscis or mouth parts trasel these sporcs in the salva of the mo quito and become injected into the mins blood stream The spores then attach themsches erch to 3 rd blood corpuscle enter and proceed ·6 MALARIA forthwath to destroy it by feeding on it The question of mile and female forms does not here arise as we are now dealing with the asexual lift of the plasmodium The plasmodium becomes bigger and bigger inside the red blood corpuscle until the time comes for it to divide The division goes on until instead of one parasite in the cell we get many which form clumps of spores known as rosettes This is now the full ripe stage of the parasite The red cell bursts and all these tiny spores zre thrown free into the blood stream only again to enter fresh red cells and there begin once more the non sexual cycle Now this cycle tikes time to complete In some cases seventy tuo hours are required Then the fever is called Quartan in other cases forty eight hours suffice for the completion of the cycle and then the disease is called Tertian and gun the cycle may take place in under forty eight hours as is the case in Malignant or Sub tertian feser It is these forms that cause the symptoms of the disease The mun symptom is fever which occurs when the rosettes burst and the parasites are thrown into the blood stream Therefore the fever will recur every third day with Quartan malarn and every second day or every day in the Tertian fesers In process of time certain of the non sexual elements of the plasmodium become differentiat

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·6
fi
C
a
t

·VALARIA 7 ed and form themselves while in the red corpus cles of the blood into spherical shapes called spheres and into crescentic shapes There are male and female spheres and male and female crescents according as the type is Quartın or Benign tertian in the former case or Malignant tertian in the latter case These forms do not cause any symptoms of fever and their sole function is to await the arrival of a certain mosquito which sucks them up into her stomach a hen she bites the individual and there they commence once again the sexual cycle is has alrendy been described It is in this manner that the complete cycle which causes the disease known as maların carries on between the mosquito and man With this knowledge grined it remains for us to discover in what wy we can endeavour to eradicate this We could for exanıple turn our atten tion to the individual and by giving appropriate drugs hill out the plasmodium in his blood Unfortunately se hne no known drugs on which we can depend for this ideal method of dealing with the disense Quinine which is ercellent for controlling the diserse has no action on the sexual forms in the blood We are therefore forced to look to the other host and find out if it can be dealt with in such 7 way that ue can brenk the link in the chain necessary for the development of the plasmodium drene

·8
MALARIA
Where there are no mosquitoes there is no
malaria Hence of malaria exists in a locality and
you want to free that locality of maları? you must
free it of mosquitoes
Thus our attention is
directed to that enemy of manhind the mosquito
which must be dealt with rigorously firmly and
unscrupulously If one nation goes to war with
another it strives to gain is complete a know
ledge as it can of that other nation and of the
armies of that nation in order that it may
supply sufficient fighting forces to overcome them
And so it is with the mosquitoes If we are
going to eradicate and exterminate the mosquito
we must get to know which mosquitoes carry the
disease what their habits and environments are
what is the life history of these mosquitoes and at
what stage in the life history are they most easily
attached
Other diseases have also been traced to the e
pests two of which are very important namely
yellow fever and filariasis
while the common
fever called dengue is also known to be spread
by mosquitoes

·CHAPTER {}
THE LIFF HISTORY OF VOSOLITOFS
ri TARIA AVD PL PA
BEFORE commencing the study of mosquitoes it
s as well that we should have some knowledge
of how these crentures are classified in the animal
Lingdom and l» shat means we can distinguish
them from other inimals At the same time we
can acquire a rough working knowledge of hors
mosquitoes are divided up into their several
families tribes groups ind so on
The mosquito belongs to the class of animals
called INCIS which are distinguished from all
others bs certain well defined characteristics
Within this dans certain groups of ninirls
Show common features
Lach of these groups
is called an ORDFR Mosquitoes belong to the
order Diths (flsey) and their particully pecu
larities are that they are one pur of me
branous sings that their mouth parts are so
constructed as to enable them to such and that
during their existence they pass from un ess to a
fuval then to 7 puprt and then to in dolc
stige or in other words
exhibit complete
metamorphosis

·10 EGG, LARVA AND PUPA their wings Again the order of Diptera is divided up into a large number of FAMILIES according to dissimi larities between certain of the creatures forming the order The family that includes all mosquitoes Is called the Culicidne and it is characterized by its members all having long slender antenna consisting of never less than six portions or segments having a definite arrangement of the veins on the wings and carrying scales on This family is too large to treat as a whole so it has to be divided up into lesser families called sub families One sub family his long mouth pirts often nearly as long as the body They bite and the veins on their wings carry scales This sub family is called the Culicinae and in it are included all the mosquitoes with which we have to deal The Culicinae are divided into four TRIBES-- the Culicını the Anopheline the illegalorhını and the Sabethinz The Megalorhını or Elephant mosquitoes are large insects with long tapering mouth parts bent downwards and backwards like a hook and the Sabethinz are forest living mosqui toes which are regarded as harmless to min but the Anophelin include all those which carry malaria and the Culicını all those which carry filariasis yellow fever, and dengue The last two tribes are once again divided up into GENERA The Anophelını have only one ·CGG LARTAAVO PUPA 11 genus se plichs while the Cuticime have at least to the Culex and tales The latter is usually spoken of is the genus 54 LOWJ\ Very fine characteristics common to groupe ithin the genera finally cause them to be seported up into different species These charac teristics are always constant in the members of the «ime species Take for erimple the genus Inopheles There are some hundred and tsenti dificrent species recognized in the sime fashion there se numerous species of the genera Cuier and Streow? and among them attention must be paid to the Culee pals, en het preads the infection of filariasis and dengue fever and to the Skoma fasta which tranamstvcllos ferer With regard to the naming of 3 smysquito there rre certain principles laid doun First of all the same must be in latin and the words used ne not luin thet mui le fatinized Secondly there are always isso pois to the name of 1 mosquito the name of the genus fellosed by the name of the species Thirdly 11n1mes must be written in alıcs and the pime of the genus begins with 1 capital while the name of the pecies commences with small letter It is in this way that the names of the mosquitoes inopheles tenerse and the (uler fargans are fred 3t These are usually written shortly thus 1 kphenst ind C fangans

·14
EGG LARVA AND PUPA
VIA
۔
wan
AM
FIG 1
FIG 2
immmmmmmorant
FIG 3
FIG 4
&
of
朗朗的
FIG 5
FIG 6
THE ONLY OR EGG
1 Cul 8% aft! tu al 1) F16 2 Cule ere raft imazmded)
FG 1 Lat al view of Fi 2
Fig L Adoph les erxs (natural size)
HO SA bh ! , exx (magn!A a) F10 6 P terns ma by Apoph les
F

·The egs EGG LARIA AND ICPA 15 differ in shape and position in different species of Anophelini and it is possible to some extent to distinguish betn een the eggs of some species of Anoplielmi by such characteristics or ovum stage usually lasts from two to four days but ma be a little less or a little more in different species and at different temperatures and then they hatch out into small wriggling animals called Lary The Larya -The larvæ of mosquitoes are well known objects They consist of a head thorax or chest and an abdomen The charac ters of the abdomen ?re very important in that they gre the read:est means of distinguish ing between the main groups The abdomen consists of mine segments The first seven ses ments ire very much alihe The eighth segment carries the external openings (stigmata) of the respiratory tubes which serie to supply orygen to the tissues of the larva in all Iuo plulım the larval respiratory tubes open directly upon the upper surface of the eighth segment The respiratory tubes of the liria of the genera Cul r and Stegons ia do not open directly upon the eighth segment but are prolonged from it into a projection which is hnown as the syphon tube Theab ence of a syphon tube is character istic of the larn of the Anophelini The length and character of the syphon tube is of impor

·14
EGG LARVA AND PUPA
CLIMALLY
۔
FIG 1
FIG 2
temammamunamatay
FIG 3
FIG 4
&
blon
WHIENT
809002
&
FIG 5
FIG 6
THE ONLY OR FGC
F1 ? Cul egy ft ( furat si el Ft 2 Cut seex raft (magulfed}
F10 3 Lt al vi w of FG
FIG Apoph le est tral size)
HOS A OPh 1 set (magnified) FiG G Patts formed by Apoph les
es

·EGG LARIA AND PUPA 15 The egg differ in shape and position in different species of Anophelini and it is possible to some extent to distinguish between the eggs of some species of Anophelını by such characteristics or ovum stage usually lasts from two to four days but may be a little less or a little more in different species and at different temperatures and then they hatch out into small wriggling animals called Larva The Larya -The larvæ of mosquitoes are well known objects. They consist of a head thorax or chest and an abdomen The charac ters of the abdomen are very important in that they give the readiest means of distinguish ing between the main groups The abdomen consists of nine segments The first seven segments we very much alike The eighth segment carries the external openings (stigmata) of the respiratory tubes which serve supply oxygen to the tissues of the larva in all Anophelını the larval respiratory tubes open directly upon the upper surface of the eighth segment The respiratory tubes of the larva of the genera Culex and Stegomz in do not open directly upon the eighth segment but are prolonged from it into a projection which is known as the syphon tube The absence of a syphon tube is character istic of the larvæ of the Anophelını The length and charıcter of the syphon tube is of inpor to

·16
EGG LARVA AND PUPA
tance in distinguishing between the larve of the
genera Culer and Slegoma, it is short and thich
in the larvæ of the genus Stegomjua while it is
long and thin in those of the genus Culer The
LEAFLET
FILAMENT
PALMATE HAIRS
the re embl I th 1 af of a ocoa D Im th
1 flets ata tra to filmt walan I dare
pect but is ths minth
ninth abdominal segment carries the anal opening
around which is uranged four large papille called
the anal papillæ hich are well supplied with ur
tubes and long curved hairs The most important
appendages of the abdomen of anopheline larva

·Q EGG LARIA AND PUPA ರಳಿನ PM TE FIG 2 TOLD TUBE Kartta F83 Fia! THE LARIS . ! DD Db 11 Pp imh AB bdom Dit 2 Tot Dh N 5 D se of Dinottes ath Ondare it with figu Mtb Dim tenirs Iclxlrv Irya AP Ip !! od mi ISID t 5 t 9 of TOH t be s gm rth ra i ingh pre + the tend ph tab s gun 18 ·20 EGG LARVA AND PUPA heads and transparent bodies They change their position at the surface of the water by jerking or darting movements and when floating in the water they take up a horizontal position They possess palmate hairs and the respiratory tubes open directly on the surface of the eighth abdominal segment and consequently they have no syphon tube The antenne terminate in two leaf shaped bodies between which a branched hur arises In must species of Anophelını a single unbranched hair prises at the junction of the proximal and middle thirds of the antennæ Larvae of the Genus Culer - These larvm form an angle with the surface film of the water and assume a hanging attitude The degree of this angle varies in different species for instance the Culer concolor assumes 1 very acute angle and lies nearly parallel to the surface film 1 hese ları & have a long thin syphon tube but have no palmate hairs They have a large branched hair projecting from the side of the antenne Larvae of the Genus Slegomyra – These larværre long and worm like and have a wrig gling mode of progression through the water Their syphon tube is short and thick and when hanging from the surface film of water they assume an almost vertical position They have no pal mate hairs Compared with the rest of the body the head is small and it is not easy to say where the ·EGG LARVAAVD PUPA 71 thorax ends and the abdomen begins They have short inconspicuous hurs sometimes as many is three projecting from the sides of the antenne The lirvil stage usually lasts from eight to twee days in the tropics and this is determined by at least tio factors viz temperature and food In colder chmates it lasts much longer Larse suing under natural conditions in collections of water grow much more quickly than those kept in the laboratory in dishes of tap uiter Lant are free swimming animals eat ori ciously and gros rapidly During the process of their grouth they cast their skins several times until they reach their final development At this stage they become much quieter and are very easily hilled by merely agitating the water in which they are found The change from the larial to the pupal stage is sudden With 3 few rapid motions the larval skın is cast off and the worm ble Turva assumes 7 characteristic commi shape and becomes the pupa or nympha (see Dragram) Certain larvæ of other insects may be mistaken for mosquito lurv because they bear a superficial resemblance to them There re for instance ları r of certain fises called Chironomus Ephe mera Dixa and Corethra They can however be easily distinguished from mosquito larve by certain pecultar characteristics of their own Chironomus lare are commonly knonin is ·22 EGG LARVA AND PUPA blood worms They are bright red worm like creatures often found in large numbers when the mud at the bottom of a small pool is stirred up In general appearance they beur no resemblance to mosquito larse Ephemera larve may at first glance be mis then for mosquito lar e but there is no real likeness Their air tubes do not open externally and they obtain the necessary oxygen from the water by means of gills the presence of which renders them easily recognizable Also the tail end of Ephemera larve terminates in a tri radiate manner which marks them off distinctly from mosquito larve These Ephemeride ire com monly known as May flies Dix? larve rather closely resemble Anophclını though not other mosquito loriæ They more along the surface of water lihe Anopheline larve and they also rest horizontally just beneath the surface film But in Dıx? there is no globular thorax all the segments are almost equal in size and the whole larva is longer and thinner than the mosquito larvt They have no palmate hurs possess four legs by which they climb up the sides of the vessel in which they are kept and are in the habit of resting in a loop with the head and tul dounwards These characters should prevent any difficulty in distinguishing these from Anopheline lırız ·EGG LARIA AND PUPA Corethra lari e are very transparent and tre for this reason known as Phantom larve They have an exceedingly small head and possess no respiratory syphon There is 3 swimming fan on the last segment and they lie horizontally rither decp in the water The Pupa or Nymph-lhe pupe of mos quitoes are characteristic creatures comma shaped in apperrnce with a large globular body and a small tail The globular body includes the head and thorax The tail includes the abdominal segments Bhen disturbed they dart dounnards uith great speed but soon reappear on the surface surface They sink in the water by making volent exertions with the tail and once the move ments of the tail cease the buoj int pupa forts up to the surface just before the hatching of the mosquito the pups becomes less inclined for atne movement and the tu may be extended horizontally Then 1 crack appears in the chutin' of the back of the thorix ad the adult insect emerges through this crich and sits for a while on the empty pupa case drying its kings and then fles 387) as the full blown mosquito In order to differentiate betueen the gener? Anophcles Cuter and Stogoms in the pupal stage great attention must be paid to the differ Chitin es bras a harc mpe beable obstance fostus 2c the covering

·24
EGG LARVA AND PUPA
ence between the syphons of these genera
In
the genus Anopheles they are stumpy and
proportionately much shorter than in the genus
Culex They have a square truncated end, and
Fig 1
FIG 2
FIG 3
FIG 4
Fig 5
mory
THE PLPA
F G Pupa of A MI
FIG 3 sphonbe 14
FIC 2 Pup of Cul
PGCyphon tube of C le
PG 3 Sypho tate : 52 ms 2.
project from the middle of the thorax while in
the Culer the syphons are long and slender
have an oblique opening and project from
the posterior portion of the thorax
In the genus

·25
EGG LARIA AND PUPA
Slej omia on the other hand the syphons are
triangular and broad and hence are very
characteristic The pupäe of the lnophelını lie
less vertically in the water and are longer and
narrower than those of the genera Culor or
Slegomia
In the tropics the nj mphal stage lasts about
forty eight hours

·24
EGG LARVA AND PUPA
ence between the syphons of these genera In
the genus Anopheles they are stumpy and
proportionately much shorter than in the genus
Culer They have ? squire truncated end and
FIG I
FIG 2
mo
FIG 3
FIG 4
*
FIG 5
THE PUPA
FIG 1 Pup of A DAY
FG 3 pbt be of A $4!
Fra 2 Pape of 1
PG 4 Sy phot be of C !
FIG 5 Syph nt be of Stecoms in
project from the middle of the thorax while in
the Culor the syphons are long and slender
have an oblique opening and project from
the posterior portion of the thorax In the
genus

·EGG LARIA AND IUPA
Sle, omynı on the other hand the syphons are
triangular and brord ind
hence are very
characteristic The pupe of the Anophclont lie
less vertically in the water and are longer and
narrower than those of the genera Culer or
Stegonia
In the tropics the nymphal stage lasts about
forty eight hours

·CHAPTER III
THE ADULT MOSQUITO OR IVAGO
THE Imago is the winged insect well known
to those living in the tropics As in all other
insects the body of a mosquito consists of three
distinct regions--the head the thorax and
abdomen
The Head carries the sensory and suctoral
organs It is more or less globular in shape and
is attached to the thorax by a narrow neck The
upper surface of the head is manly occupied by
the two large compound eyes The portion of
the head which lies between the eyes is called the
vertex while the frons is that part sluch lies in
front of the vertex Immedıntely behind the eyes
lies the occiput while the nape is the portion
behind the occiput at the extreme back of the
hend The prolongation of the frons anteriorly
is spoken of as the clypeus Immediately in front
of the eyes on either side rise the antenne
These are long jointed structures provided with
hairs and consist of fourteen to sixteen segments
Beneath the clypeus prises the proboscis The
proboscis is a collective term given to the highly
specialısed mouth parts which consist of the upper
See Fror los prece

·THE MVAGO 27 lip the lower lip the tongue two mandibles tuo maxle and so maxillary palp: The lower lip or labrum is a grooved structure enclosing the other mouth parts and forms the thick scaly proboscis as usually seen The two maxillary pripn lie on erther side of the proboscis and are of generic and specific importance Each prip consists of four segments The Thorax carries the locomotory append ages in the form of one pair of wings and three pairs of legs The anterior portion of the thorax is 1 collar hle piece of chitin and as called the prothorax while the middle portion is called the mesothorax and forms the large globular mass of the thorax Behind the mesothorax a prominent ridge called the scutellum runs betnen the bases of the wings Behind the scutellum 1 horse shoe shaped area called the post scutellum can be readily distinguished The scutellum and post Scutellum are of importance in the classication of mosquitoes The wings of mosquitoes are long with an anterior straight border called the Costa u hich in tropholını is usually covered with white and black scales forming the spotted margin There is also a posterior cursed border fringed with long sozles forming the sing fringe In Anophelını this has also light and dark portions the extent and position of which are made use of in the ·30 THE IVAGO tinguished from the female by observing with the aid of a hand lens that, whereas the male antenne are markedix feathery or plumose, the female have only short lateral hairs and whereas the male palpi tre long and hairy the female are much less conspicuous Another difference lies in the fact that the female feeds on blood whereas the male prefers to such vegetable juices There are some members of the order Dipter (files) which may be mistaken for mosquitoes Mention will be made of the chief ones which can be distinguished by noting a few chara. teristics of ench First there are the Chiru nomides (Midges) which do not possess the characteristic proboscis of mosquitoes Their legs are long and slender and the veins of their wings do not have scales Then there are the Tipulido (Daddy long legs) which have no distinct pro boscis and possess long slender legs the Simulida (sand Ales) which are tiny insects with a short stout proboscis and lastly Rhyphus fenestralis ? fly often seen on windous which may be mistaken for Anophelını as its wings are spotted but there are no scales on the wings and the second longitudinal vein is not forked In the identification of mosquitoes it is neces sary in the first instance to observe whether the insect under consideration belongs to the order Diptera (Ares) This is determined by observing ·THE NIAGO 31 It hether the mouth parts are constructed for biting or suching and whether they have one Pur of membranous sings Once it is decided that the specimen belongs to that order the possession of scales on the wings and body and the characteristic oing enation #ill place it in the fimily Caledr while the sub famıly Culica will be chosen the specimen carries scales on the veins of the wings and if the mouth parts are made for bsting If the specimen is a Cultura it is necessart still further to determine its correct tribe whether it be Anophelını or Cult int It will be sufficient for our purpose of we observe the distinguishing features between these tlo tribes it being understood that should the specs men not fulfil these conditions it probably comes under the heading of some other tribe It is essential in distinguishing the Anophelem from the Cu ani to observe the wings rule those of the former are spotted while the latter are not 1 hese spots are caused by areas of white and durà scales on the veins and always occur usth no pheluz except in certain species three of which are found in Indir and must be care fully noted They are of athen onraurusis and & culators Whereas nearly all the species of the Culiem hue uniform dark wings the Cmimeticus has costal spots *s a rough guide this differentiation is exceedingly valuable Again As 1 ·32 THE IMAGO the proboscis of the Anoplelini continues in a straight line with the body while in the Culıcını it forms 1 distinct angle This accounts for that characteristic attitude adopted by these tribes #hen resting on the wall The body of the resting Anophelını forms a distinct angle with the wall 1 hereas the Culicinz appear either parallel to it or have r hunchbached appearance There is hon ever an exception as the A culicifacies 1 common mosquito in India holds its body horizontally as do members of the Culicını Again the palpı are long in both the male and female Anophelin whereas they are long in the male but very short in the female Culicint The most accurate and scientific distinction between these two tribes lies in the fact that the scutellum of the Culici is trilobed whereas the scutellum of the Anophelını is simple and never trilobed "This observation however is not easy to make with in degree of accuracy with a hand lens and requires repeated and constant practice to become expert but with a microscope this difference can readily be seen As there is only one universally recognized genus of the tribe Anophelını once a mosquito is placed in that tribe it naturally becomes classed in the genus Anopheles There are however at leist tuo genera of the Culıcını the genus Culer and the genus Stegomjua (Aedes) which must be distinguished

·THE IMAGO
33
Alosquitoes of the genus Stegoria are popularly
known as tiger mosquitoes on account of the
prominent alternating white and dark stripe like
arcas seen on the abdomen and legs of some
species of this genus Unlike other mosquitoes
they can be seen feeding during the day but
Fra 1
FIG 2
46)
CULEX
STEGOMYIA
HEAD SCALES OF STEL OMNIA
гоw са а а гъ у епне тwith
I w apright t kea
I HELD CALFS OF CLLEX
FI tils ry1 d ply to id Thy re mos ly
curved & des ed som pight forked
rrow
these features can by no means be relied upon is
an accurate and scientific means of distinction
Although these two mosquitoes are obviously
distinct yet many mosquitoes : hich at first sight
appear to be identical are often found to be
quite different on examining their scales The
head scales in the gener? Cuter and Strgomzia
are quite different and are of importance in

·31 THE IMAGO the identification of these two generı (vide plate) All mosquitoes of the genus Culcr have on the head mostly narrow curved and upright forked scales but only a few flat scales laterally whereas all mosquitoes of the genus Stegomra have on the head practically all fiat scales with only a feu upright forhed and no narrou curied scales at all Further the clypeus in the genus Stegomia is scaly while in the genus Culer it is hairy These differences can only be made out with the aid of 7 microscope Having now determined the exact genus to which z mosquito belongs it is necessary to proceed to the final step of the identification of the species As so far only Anophelın have been incriminated in the transmission of maları? it will therefore only be necessary in this book to deal with that genus The most important distinguishing features are the following and one should get thoroughly acquainted with what they are and where to look for them so that deviations can be easily detected and the species therefore identified Each inspector should by practical experience make himself thoroughly familiar with the use of the hand lens before he can hope to become expert at distinguishing these minute characters The Costal Spots --The spots on the sing ·THE IMAGO 33 are caused by patches of white and dark scales on the costal vein the sub costal sein und vein I The costat spots are fairly constant in each species and the number and extent are of con siderable importarce in the determination of species The Palpal Bands Hest gain patches of *hite scales occurring it the junction of the palpal segments give the appearance of white bards These are also fairly constant in each species The presence of such bands their number and extent are all made use of in the determination of species in 4 barbirostris for instance there are no white binds the whole palp being dark scaled In koche there are tave uhite bands in Ahrernus there are four white bands and in A ulicifacies there are three white binds so that each individual species his invariably got definitely marked palpi The Wing Fringe -At the points of jung tion of veins 1 to 6 pith the costat rein which passes right round the wing sometimes light areas occur due to the presence of white scries Such light areas differ in different species but are fairly constant in the same species in d entafacies for instance there are not mort than trolight areas on the sing fringe while in the A liston there are six light areas The Wing Veins Here again the presence ·36 THE MAGO of dark and white scales on the wing veins causes definite dark and light areas in the wing field u hich are furly constant in the same species In A culicifacies for instance vein 3 is almost entirely dark except for a small white area at its commencement whereas in A stephensı the third vein is almost entirely white except for two small dark areas one near its commencement and the other near its termination The Legs Banding of the legs, like those of the palpi is also of specific importance It must be noted whether binding is present in each segment and if so whether it is apical basal or both whether any segments are completely white and so on In A subpictus for instance the front tarsal segments are distinctly and broadly banded In A theobaldı the last two hind tarsal segments are completely white, while in d inlicifacies none of the tarsal segments is white Speckling This is a condition which in some species is present on the legs or on the palpi or on both When such a condition exists the palpi or legs look as if they are distinctly murhed tith white and dark spots the best way to get familiar with this condition is actually to look at a specimen with speckled legs or palp: and when once seen it cannot be mistaken A stephense for instance, has speck ling on the legs and palpi Atheobaldı has only

·THE IMAGO
37
speckled legs, whue i subpictus has neither
spechled legs nor palpi
All these conditions could invariably be made
out by means of a hand lens (10 to 20 times
magnification) and with a little practice the
identification of species with the aid of a synoptic
table is a simple procedure in the large majority
of cases
Such synoptic tables have been pub
lished by different authors and as an appendix
will be found the synoptic table issued by the
Central Malarial Bureau hasauli 1926

·36 THE IVAGO of dark and white scales on the wing veins causes definite dark and light areas in the wing field which are fairly constant in the same species In A culicifacies for instance vein 3 is almost entirely dark except for a small white area at its commencement whereas in 4 stephensı the third vein is almost entirely white except for tuo small dark areas, one near its commencement and the other nezr its termination The Legs — Banding of the legs like those of the palpi is also of specific importance It must be noted whether banding is present in each segment, and if so whether it is apical basal or both whether any segments are completely white and so on In a subpictus for instance the front tarsal segments are distinctly and broadly banded In A theobaldı the last two hind tarsal segments are completely white while in d culicifacies none of the tarsal segments is white Speckling –This is a condition 1hich in some species is present on the legs or on the palpi or on both When such a condition exists, the palpı or legs look as if they are distinctly marked with white and dark spots the best way to get familiar with this condition is actually to look at a specimen with speckled legs or palpi and when once seen, it cannot be mistaken A stephensı for instance has speck ling on the legs and pulpi A theobaldı has only

·THE IMAGO
37
spechled legs while 1 subpictus has neither
speckled legs nor pilpi
All these conditions could invariably be made
out by means of a hand lens (10 to 20 times
magnification) and with a little practice the
identification of species with the aid of a synoptic
table is a simple procedure in the large majority
of cases
Such synoptic tables have been pub
lished by different authors and as an appendix
will be found the synoptic table issued by the
Central Malarial Bureau hasault 1926

·CHAPTER IV
THE HABITS OF MOSQUITOES
BEFORE entering any given district for the
purpose of taking anti mosquito measures the
squad with its inspector at its head wall have
been made acquainted with the types of mosquitoes
that they are likely to encounter This
gives
the
hey to the solution of the problem which faces
them as to where they are to looh, not only to
encounter mosquitoes but to discover where they
are breeding This information is received from
what is known as a survey of the district and is
generally undertaken by expert entomologists
and their trained assistants A catch is made of
all mosquitoes that can be found in the district
and also any larvæ discovered are carefully pre
served These catches are made throughout a
whole year and months which show a large
increise in numbers are noted The mosquitoes
are classified and preserved under their several
names and large numbers are dissected to
discover in what proportion the various mosqui
toes carry malaria in nature As a result of
this information a plan of campaign is put forward
which will aim at the elimination of the breeding
places of such mosquitoes for if mosquitoes are

·THE HABITS OF MOSQUITOES 39 not allowed to propagate they will be gradually eliminated Armed then with a complete list of the various kinds of mosquitoes the inspector will be put well on the way to discover their whereabouts because experience has taught us many of the ways in which the various species live and propagate It is common knowledge that marshes breed mosquitoes and operations on a large scale have been undertaken at great financial outlay to drain them but sometimes without any diminu tion in the amount of malaria in the surrounding country In some of these cases it was not until more careful observations had been made of the habits of the mosquitoes carrying malaria that the channels themselves built to drain the murshes were found to be the offenders as they harboured the larvæ of 1 mosquito which bred in running water Thus the object of the undertaking wis not fulfiled through lack of a thorough knowledge of the habits of the various species of mosquitoes in that district We approach the subject of the habits of mosquitoes first of all from a general aspect These insects whose persistent annoyance is the source of much incovenience and distraction to all who have lised in areas where they abound usually pester their victims in the night and one of two courses both very apt to prove a false 7 F ·40 THE HABITS OF MOSQUITOES ing hours security is sailable as n protection during sleep Either the individual must cover himself with a foul smelling oil sıhich although repugnant to the none too refined tastes of the mosquito is much more repugnant to the unfortu nate person trying to get a nights repose, or he must sleep under a mosquito net which will by the closeness of its meshes heep out the cool gentle night breezes so refreshing on a hot tropical night and much of the current of air caused by an electric fan Unless the utmost care is exercised that the net is properly used and kept in repair he will zwake in the morning after a hot restless night to find sitting in one corner of the net tuo or three of these pests gorged suth his own blood too sleepy to fly away from the consequences of the saiage a rath they engender in the breast of their victims Far better it hould be to sleep without a net in a bungalow not hampered by mosquito proofing and awake refreshed from 1 sleep in the open wir in the cool breezes untroubled by the attacks of these winged pests Generally speaking we dide the mosquitoes into two great bands We have those which inhabit the vicinity of houses stables cattle sheds, and so on They love and breed in and around them and their life is lived in a very circumscribed area These we may call' House ·THE HABITS OF MOSQUITOES 41 hold mosquitoes Then we have those which live in the surrounding marshey rivers and streams and fly to houses for protection from the heat of the day and for the purpose of sucking the blood of mammalia--these we may call Country mosquitoes Although it is not arbitrary these two classes may roughly be said to include in the former the Culıcını and a few Anophelını and in the latter most of the Anophe lint and some Culicine Again it is not all mosquitoes which will bite human beings-only the females The female wall feed upon mammalia after she has become fecund ated as it is generally understood that blood is necessary to her for the true development of her ova It is generally accepted that males never suck blood The adult male remains more or less in the vicinity of the breeding place and meets his mate after she has hatched from the pupal stage or has arrived and laid her eggs Mosquitoes as a rule have many sources of food supply Fruit and vegetables of various kinds especially if they be over ripe and mammalian blood are their usual diet The female wall not select a spot for laying her eggs where there will be no food for her offspring Thus dirty water gully trips and cesspools are popular breeding places of the Calıcını while clean water marsh or ponds with vegetation are frequented by the ·12 THE HABITS OF MOSQUITOES Anophelını Of course, 1 hen driven to it they may deposit their eggs and larvt may hatch out in water where no suitable food appears to be but for preference the other more suitable sites yre selected During the heat of the day mosquitoes will seek out sheltered spots to escape from the sun which they do not like Thus they are found reposing in the shade amongst long grass or under the leaves of trees and it is this phenome non which has given rise to the erroneous impression that long grass and undergrouth necessarily breed mosquitoes and drastic opera tions have been undertaken to rid occupied areas of them often rendering pleasant and beautiful districts desolate Mosquitoes breed in receptacles concealed in grass and undergrowth and in the hollows of trees where water can accumulate after rain If these are properly dealt with as will be mentioned later, it will be unnece.sary to spoil beautiful gardens and remove the benefits of shade by the destruction of trees day mosquitoes may also be discovered hiding in houses from the heat and sun especially in dark corners cupboards presses and among clothes hanging up They are not generally found in the vicinity of cooking ranges, but Anophelını have often been found reposing on cobwebs looking like tiny little bits of dirt hanging downwards During the

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THE SFA HORE AT COLAB4 BOMBAY
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·43 THE HABITS OF VOSQUITOES As evening approaches and the day cools they come out of their hiding places and feed and in most species the female then seeks out warm blooded animals After having fed on them and being ready to lay her eggs she proceeds to the breeding water and lays them on its surface There she finds the male awaiting her and once more she mates with him and the whole proces is repeated It must als zys be remembered that of a number of male mosquitoes are discovered in any one locality it is an indication that there are mosquitoes breeding nearby Having grasped these few points we will now pass on to consider the haunts of the various generi of mosquitots The Culıcını select breeding places which provide food for their young For this purpose Cesspools gully traps and collections of dirts Hater in and around houses stables and cow sheds are their favourite halints and here they ve also near their mammalian food food supplies xcept for the genus Slegoma which are day feeders they mostly feed at night During the day they hide themselves in cool corners cup boards amongst clothing and so on in order that they may escape the heat and glare of the tropical As evening approaches they come out to feed and they become annoying till dawn when once more they seek shelter from the oncoming heat The adults are most easily caught during tun ·44 THE HABITS OF MOSQUITOES the day time if diligent search be made for their places of concealment They are seen sitting patiently in their typical positions and a glass tube can be gently and slowly passed over them In the evening they fils about and are not so casily caught but with nets they may be captured after ? little practice Their larvæ can be discovered in wells gully traps open druins cess poois tanks and old tins which have been left lying about Old barrels motor tyres cigarette tins and bottles will all hold water in the rainy season and are favourite sites for ovpositing with many of the mosquitoes In the compound should you find trees they should be searched carefully with a vieu to discovering whether there be any holes which retain rain water Long grass and rank vegetation in themselves do not breed mosquitoes but they are splendid positions for mosquitoes to take up during the heat of the day and they harbour all sorts of tins bottles and rubbish which catch rain and afford excel lent cool water in quiet spots for breeding Thus itull be found that when search for mosquitoes in and about a house has proved unsuccessful and just 15 you are about to abandon all hope of discovering any breeding places, your attention is arrested by that corner of the compound which in many households seems to be a sort of dumping ground for odds and ends And there amongst ·E larvæ and pupa Oter than re 25 : bers the 12 non ho стресу. THE HABITS OF MOSQUITOES the grass is an old rusted tin with its broo Mor do even the most i cent looking bamboo poles used as supports sheds and lean to buildings escape The fei bamboo is a hollow structure and should ther any cracks or holes in it run water wall co and breeding will certainly result Within the house itself the careful inspe will generally find certain spots which are li places for breeding mosquitoes Among the water cistern which has not been rend mosquito proof and the waterserls of wash d unter closets which are not in daily use ma mentioned Flower vases and antı formicas or holding water which are placed under the les tables to prevent ants from swarming up food placed on them have very often been covered to harbour ları The utmost must be taken by the inspector to trace ou possible vessels containing water These must strive to have emptied daily and an them are the earthenware vessels called cha which are in common use in India If one were to turn one s attention to multiplicity of breeding places that can dail discovered in cities especially in factories jards volumes could be filed dealing with inspectors work Suffice it to say that on principles et olved in this chapter the intelli etnery the asy, ea 1 fliek ba ordere! at entus indet dorp ·46 THE HABITS OF MOSQUITOES searcher will soon discover all the important breeding places provided he has the co-operation of those living and employed in any establishment he may visit The Anophelını are usually found breeding in the country although certain species eg stephensz and A sub pictus are frequently to be discovered breeding in water cisterns and especi ally in wells in houses and compounds But generally speaking the Anophelını for example A maculatus and A theobaldı, live in marshes, river beds and jungle pools The female flies to the habitations of man and his domestic animals to feed upon blood and thus during the day she may be found freely in infested houses in just those places where the Culicını are found As a rule they attack their victims at night, but here again we may come across exceptions as certain species bite during the day while others appear to reseile their energies until the early morning Having fed upon blood she then flies back to her jungle pool marsh river bed or seashore and there lays her eggs and once again in the vicinity she finds the mile awaiting to mate with her and the whore process is repeated People often ask how far a mosquito can fly With a wind behind them they can certainly travel great distances, but against a wind their range is naturally more limited But ·THE HABITS OF MOSQUITOES 47 some maintain that if the wind be not too strong distance of flight is affected very little Generally speaking Anophelını live within a radius of one mile from their human food The adults in flying from their breeding beds occasionally show most erratic habits They will for example find their way not to the first house in a village but to the last missing out houses in a curious manner Adults are very conservative about their breeding haunts and return to them time and time again Most species show the extraordinary habit of leeping to the same type of breeding place Certain species for example breed in the shady pools of jungles and will not breed anywhere else Again other species breed in the running water of streams and will not breed in still shady pools It is now very generally accepted that the different species will not alter their methods of breeding and once the places have been eliminated the species dies out They do not appear to be able to carry on as that species unless the conditions of breeding common to the species obtain Thus it comes about that the inspector who knows the mosquitoes which are breeding in his district will also know where to look to find their breeding haunts It has often been stated that mosquitoes do not breed to any extent in sea water This is not our experience in Bombay where the A stcphensz ·48 THE HABITS OF VOSQUITOES d subpictus d culıcıfacies and A agus huve all been discovered breeding in salt water on the sea shore On one occasion the water was three times as salt as sea water However there are strict limitations to their breeding on beaches We have always found them in pools among rocks on that strip of the beach which lies between the high water mark of spring tides and the high unter mark of neap tides The presence of mangrove and other vegetation increases the likelihood of breeding in such areas Mosquitoes have not been found breeding in the open sea or on that part of the seashore where the daily rise and fill of the tide tale place The breeding places of mosquitoes can be divided into two great classes permanent and temporary Bentley in his work on malaria in Bombay has demonstrated that the chief carrier of maların in that city is the A stephensi This mosquito is known to breed all the jerr round in wells water cisterns and pools on the sershore They are usually found in small numbers in these sites and it is thought that their natural enemies prevent them from becoming too numerous When the monsoon breaks, rainwater pools and a variety of collections of water become abundant throughout the city and the mosquitoes spread from their permanent breeding places to these temporary ones, and this results in the appearance ·the city THE HABITS OF YOSQUITOFS of multitudes of mosquitoes capable of carrying maltria Within a short time maria rages in When the monsoon ceases and the temporary breeding places dry up and exist no longer then the mosquitoes return to their per manent breeding sites and consequently the incidence of malaria drops Our experience in Colaba confirms these observations Per manent places there breeding occurs are those positions in which water can be found throughout the yerr They include wells water cisterns Sarden tanks pools in river beds streams water channels and so forth Temporary breeding places are such as occur during rains and include collections of water in storm water drains, sheets of water on the ground and the numerous sites about a household already enumerated We give at the end of this chapter a list of Indian Anophelm ind it is recommended to the careful study of every inspector However there is another way in which mosquitoes »]] remain alive when conditions are not talourable for their propagation Should the weather be too hot or too cold to favour their continued existence then adult temales which are about to lay their cggs seek out some quiet cool spot and there settle dos n and pass into a torpid state in which they seldom if at all feed and appear to be asleep If this occurs during cold months it is spoken of ·48 THE HABITS OF MOSQUITOES d subpictus A culicifacies and Angus have all been discovered breeding in salt water on the sea shore On one occasion the water was three times as silt as sea water However, there are strict limitations to their breeding on beaches We have always found them in pools imong rocks on that strip of the beach which lies between the high water mark of spring tides and the high water mark of neap tides The presence of mangroie and other vegetation increases the likelihood of breeding in such areas Mosquitoes have not been found breeding in the open sea or on that part of the seashore where the daily rise and fill of the tide take place The breeding places of mosquitoes can be divided into two great classes permanent and temporary Bentley, in his worl on malaria in Bombay has demonstrated that the chief carrier of maların in that city is the A Stephens This mosquito is known to breed all the year round in wells water cisterns and pools on the seashore They are usually found in small numbers in these sites and it is thought that their natural enemies prevent them from becoming too numerous When the monsoon breaks rainu ater pools and a variety of collections of water become abundant throughout the city and the mosquitoes spread from their permanent breeding places to these temporary ones, and this results in the appearance ·THE HABITS OF VOSQUITOES 49 the city of multitudes of mosquitoes capable of carrying malaria Within a short time malaria rages in When the monsoon ceases and the temporary breeding places dry up ind exist no longer then the mosquitoes return to their per minent breeding sites and consequently the incidence of malaria drops Our experience in Colaba confirms these observations Per manent places where breeding occurs are those positions in which water can be found throughout the year They include wells water cisterns garden tanks pools in river beds strerms water channels and so forth Temporary breeding places are such as occur during rains and include collections of water in storm water drains sheets of water on the ground and the numerous sites about a household already enumerated We give at the end of this chapter a list of Indian Anophe'ını and it is rerommended to the careful study of crery inspector However there is another way in which mosquitoes will remain alive when conditions are not favourable for their propagation Should the weather be too hot or too cold to favour their continued existence then adult females which are about to lay their eggs seek out some quiet cool spot and there settle down and pass into a torpid state in which they seldom if at all feed and appear to be asleep If this occurs during cold months it is spoken of

·50 THE HABITS OF MOSQUITOES
7s hibernation A similar condition may occur
in hot dry months in the tropics and then the
mosquitoes are said to aestivate
The manner in which mosquitoes become dış
tributed over a given area is interesting They
may be and are blown to considerable distances
from their breeding haunts by strong winds and
being unable to return they are perforce obliged
to seek out fresh collections of water in the
neighbourhood ind though it is usual for mos
quitoes to return to the vicinity where breeding
abounds yet it is not always so Some may arrive
at fresh water collections which have a plentiful
supply of food for larvae especially those to the
leeward of the habitations to which the adult flies
for its mammalian food Again irrigation chan
nels can carry larvæ a long distance and those
surviving start new foci further down the channel
The age to which an adult mosquito may
lite
has not been worked out for each species
The
males are much shorter lived than the females
The life of a female may be put at any w here be
tween six weeks in certain species to three months
in others

·PABLI or iOPII I INI (INDIA) SHOWINC DISTRIBUTION AND BREEDING HABITS NAME OF TECTES DISTRIBUTION BREEDING HADITS REMARKS 7 1/he 11--Jumes har sur Front of Con Bengal Duar In mans Burnt Ass m 5 Ind: lireer nogle por is rests)e Cilat rr Icels un sha led nrg the day fht der sirut-- Vandr 1 p Thr ughout lodsa Ani the Andaman I that Breves 18 halv pools in juttles orthods ant gin'cos Not (mmonls foutij in hos ses THE HABITS OI MOSQUITOES r beet clara res-> Pxis of rainutes Fly fod. And pool 2 Co rics te protest dely 11 tributed dry Bree is ani in Natur lh thr gfi ut Ind27 IT e-Ler any collectat Ir tapo has un tte le en f iter includtstot mlar to cint or chibiter hark? Honba with intre 11 M15 -Copili Rretxsinh les of trees CA A foſt rests Zihe Cultcint IS ·TABLE OI ANOPICLINT (INDIA) SHOW IN DISTRIBUTION AND BRFEDING HABITS-(Conld) un NANE OF SPECIES DISTRIBUTION BREEDING HABITS REMARKS vi fuliginosus-Giles Throughout the whole Pouls ponds and tanks of India and Burm up with vegetation at sides to 3 000 feet A swamp breeder Carries the parasites of malan in Qature Found more especially in cattle sheds Aguas-Giles A hill species fcunt in the Nilgiri Hills and hills of Southern India also Ilimalay 29 Breeds in pond and the dew ponds of Sumla Hills Awild muito bit rarely seen in houses THE HABITS OF MOSQUITOES horrinus-Pallas Bengal Ijab Bom Lay and Madras Presi dencies Breeds in sy amps and water with much vegeta tion and in nice felds Curies parasites mali in nature reeds mostly by day and not often found in houses james--1hcobakt Bengal Central Iro vinces and parts of South India Madras City i roy portch$15-Jams 10 Jeypore Agency (en Breeds stre mus tral Iroyin es and puts irrigation channel of Southern India Tice fiel 13 of ·HS been sofected th the parasit f malti 10 B mbay Irodn) Ce tral India at Assam kir'in James latxratory 1 kxhi-Denitz Assam Fr har po 1 peti si und Burm? As im Born A leucosplyus-Denitz bay South India Breels te ide rest stre ins Ferest ah nantly in coolie buts Spected to carry pari sites of malaria 1 lon tesant les Himal, und hill of South on Ind17 THE HABITS OF VOSQUITOES Bred in tr 1 hills Hul pocies ts am Berars Central Pro vinces Bengal bus Jyptu Agen) G Notoriou Bombay Hyderabul bred 1 Xec 20 Nth Canara Intrict Ceyko Asan of pars ites listol 1--Lita Carri inalna Beng 1 Burn And en as of 1 lt dlou 11- The Ind Chiefly a salt 1 ater breed fond not far fr m selhe pam ites Carries malaria 53 ·TABLE OF ANOPHELIVI (INDIA) SHOWING DISTRIBUTION AND BREEDING HABITS-(Cenld) 5+ NAME OF SPECIES DISTRIBUTION BRECDING HABITS REMARKS maculatus-Theobald Bengal Duars North west llimalayas South India Breeds in streams Carries par sites of malaria A maculopalpis-Giles (enerul India throughout Pools which may be con nected with hill streams Carnes the parzites of mainni THE HABITS OF MOSQUITOES minimus-Theobnld Assam Bengal Cen tral India (rare) Stream breeder and pond Carries the parası es of mallit 1 pallians--Theobald Centrul I rovinces Rice fields borrow pits but not flowing water A plushens 177 17 anensis. James Vestern Ilarralay as above 6 000 ft la the hollows of trees During day found in ho lows of trees Inters hc uses m thing and night to f ed ·d pulcher Is-Theo b 11 No tb West F ntr I nj b specjally the west Un ted Irosinces Bumubay Presidency Ia halle polen ra unater poils I rio testeisis-Th b 11 Bala titan kohat Quelta Similar to A clict ficies stephe ist-L ton Thiro ghout Intl Notorious well breeder Als any collect: ns of Notorio carrier of the fresh a er breds pirmites of muları1 freely in sea water THE HABITS OF MOSQUITOES 1 suferul s-Gros North West Fatir chiefly Qetta Brets 10 por la in stream beds rates the prstes cf mal ria A subpictas-Crass Throughout Ind its Shallot pol paddy May rry parisites of tra id temp rar, por is ularia but in th tight derti y to nff ct mi h thneiden breed in It water of th di se d lessclass-Th ob 11 Rare so Indit buttony be f und 1n Assard (n tral and South toda Il est Lorst Burda Suid cane brakes ·CABLE OR ANOPHELIAI (INDIA) SHOWING DISTRIBUTION AND BREFDING HABITS--(Contd) 56 new NAME OF SPECIES DISTRIBUTION BREEDING HABITS REMARKS d the bilds--Giles West Cort and Cen tral India Swamps and margins of lakes nad streams Iur Khudi-liston Berls Central Prom Breeds in clear pools Lanarests like Cuer al visces ha hmir Punjab and pools in saniy nyer surface of water Carties North West Fr utier beds parasites of malaria THE HABITS OF MOSQUITOES Azrus-Donitz Burma Assam Ben gal Monsby Clean fresh water and bruch b pocs on se? hore A ll» 111-James Tooth is of Himalayas up to 6000 Et from erst to res Breais a treams od clear jool Carnes pirasites of mm3

·CHAPTER V
PREVENTIVE WORK
BEFORE describing in detasi any measures on a
large scale shich may be undertaken to eliminate
75 far as possible the mosquito pest let us con
sider for a moment the main criticisms with a hich
the advocates of an ut mosquito scheme tre
sure to be faced Several aspects of the question
are bound to be brought forward for criticism
and it is well that all ho are more educated in
these matters should have a ready answer
One of the first comments will be that it is
a quite hopeless tash to exterminate all mos
quitoes and therefore it is a waste of time and
money to attempt it
It is difficult to convince
the uneducated of the futility of taking up such
position When the armies in France in the
Great War nere worried beyond measure by lice
and fleas it was not proposed to kill 3}} the lice
and fieas to free them of thesr troubles Life
was made well nigh impossible for surh parasites
7s require man as their host by the free use of
insecticides frequent bathing daily change of
clothing where possible and disinfestation at
properly prepared stations And so it is with

·58 PREVENTIVE WORK mosquitoes We do not advise extermination out of hand but a prolonged campzign based on a sound knowledge of the life and habits of certain tribes of mosquitoes well known to be inimicable to the health and comfort of man Another criticism but one much more difficult to dispose of is whether the large and oft times vast expenditure which will be incurred by public communities and private concerns in the launch ing and future muntenance of an antı mosquito campaign is worth while This is too large a subject to be dealt with in this small book but in all cases the pros and cons must be carefully weighed and from this point of view all schemes put forward should be as economical as possible and should be adjusted so as not to overlap the work of other departments in a community-for example the work of the Sanitary Department The saving to a community of hours of labour and many valuable lives besides the reduction of expenses in hospital maintenance should be reckoned as valuable assets In this connection one should be conversant with the work on The Preuentron of Mlalara in the Federated Mala; States written by Sır Malcolm Watson Many laudable under takings have ended in disaster through the neglect of anti mosquito measures The Panam? Canal Scheme w us attempted several times before a successful issue was achieved for this very ·PREVENTIVE WORK 59 reason and loss of reputation vast sums of money and many human lives resulted from the neglect of not incurring in initial expenditure on antı mosquito work It was not until it was realized that due regard must be paid to the mosquito that large sums of money were forth coming to undertale 1 cimpugs and only then 1 as it possible to see the completion of the Panama Canal Within our limited experience we know of several important business Concems which have came to inglorious ends because their directors failed to realize the part that the mosquito przed in the success or failure of a commercial enterprise in commercial houses established in India at $s the custom to maintain their stafts on a basis of allowing annually for a very large percentage of sickness almost wholly malars? As we have already explained the links in the malarsıl chain are the plasmodium the human reservoir and the drophchine These three links are absolutely neces ary for the chain of malini infection If any of them be absent then maların Canrot exist, thus it follows that the lines of defence and offence should naturally be directed against the destruction of these links thus rendering the chain impossible Apl defensae measures will be based on the voidance of human reservoirs and infected drophilu v hile ·60 PREVENTIVE WORK offensive undertakings will be directed against the plasmodium in the infected individual and prosecuted with a vien to the destruction and if possible extermination of the Anophelını con cerned Measures to Avoid the Human Reser voir --The system of cantonments in India where the troops are located away from the crowded quarters of the city is a very good example of the advantage accruing from this method The troops are thus frequently spared the risk of infection by Anophelını which have fed upon the human reservoir in the city and it is well known that the malarial incidence in a cantonment is distinctly lower than that of the adjoining city The moral that we learn from this is that in the location of new sites for human habitation factories mills labour lines and so on one should always take into consideration the state of endemic malaria in the adjoining places and then decide on a suitable spot All houses situated in mosquito infested areas should be rendered mosquito proof by means of wire gauze the mesh of which should never be larger than sixteen to the inch In hospitals and houses persons suffering from malarial fevers should be screened so as to prevent the anophelını becom ing infected and thus trinsmitting the disease to others in the ward or household

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SEARCHING A POOL FOK LAKTAF
SPRAING POOLS WITH LARI ACIDE

·PREVENTIVF WORK 61 Measures to kill the Plasmodium in the Blood of the Human Reservoir --This vir tually means treatment of infected persons by quinine which is the only drug se know that wil act on the plasmodium Unfortunately the suc cess of this method depends on the regular and prolonged administration in suitable doses of a drug which unless very strict precautions are taken to avoid loopholes either in its preparation or administration is liable to be abused for quinine is an expensive drug and by no means in attractue medicine to swallow Instances do exist however especially in Italy where this method of malarial control has been used with success Measures to Exterminate the Anophe line This method strihes at the root of the matter and will therefore constitute the ideal weapon in our hands We can hill the enemy either in their stage of existence in water collections or hen they are on the wing It is odious hou ever that it is much easier to attach the mosquito in its aquatic period of existence than to hunt after it when it is flying All living crentures have their enemies both natural and artıhcial and the study of these enemies my reveal a Very efficient method of dealing with mosquitoes The Natural Enemies of Mosquitoes The adult mosquitoes can often be seen falling a prej to birds buts lizards ants etc and certain ·62 PREVENTIVE HOR species of fish also attack and devour them when they approach sufficiently near the surface of water Though a number of mosquitoes can be destroyed in the adult state by such enemies it is probable that this loss is small compared to that caused by the natural enemies which attack the insect in its larval state Amongst such natural enemies fish take the first place Un fortunately all fish do not eat mosquito larve but only certain species Amongst the fresh water fish that eat them are the following Anabas scandens, Haplochtlus loncatus, Polzanthus cupar nus Barbus stigmata a species of the genus Ophiscephalus and Macrones The sea water fish that are known to eat mosquito larvæ are the Therapon jarbua and a species of the genus Mugil It is probable that there may be several other species of fish which feed on them Should any collection of water be met with there fish are present and mosquito larvæ absent it is worth while testing whether the fish cat them Put some of these fish in a suitable glass vase and put some larvæ sith them and watch the result As some fish do not eat the larie as soon as they see them, it is best to observe the experiment for twenty four hours Where there is much weed and floating vegetation in the water mos quito larvæ take cover under them and defy the fish The use of fish as lursal eaters opens out ·PREVENTIVE WORK 63 immense possibilities of successfully preventing breeding of mosquitoes in permanent collections of water especially where there is no vegetation There is no easier method of dealing with the pest Certain aquatic insects such as water boatmen and some beetles and bugs also destroy mos quito larva Some plants such as that which is commonly known as the rootless duckweed are also said to be their natural enemies The successful use of these natural enemies is a matter of individual discretion on the part of the person carrying out mosquito destruction The Artificial Enemies — The artificial enemies of mosquito ları t tre what are known as larvacides The most commonly used larvacide is oil which by blocking the respiratory passages of the larvae suffocate them herosene crude oil castor oil and gingells oil are some of the oils that are generally employed either alone or in different combinations The most commonly used com bination is a muture of equal parts of herosene and crude oil A mixture of crude oil and crude carbolic acid (20 per cent) in equal parts has prosed highly satisfactory in our experience Various disinfecting Auids such as Cresol Izal and Newcol are also highly lar acıdal The employment of disinfectants as larvacides is depen dent on the correct strength of dilution of the disinfectant An insufficient amount of disinfec ·62 PREVENTIVE WORK species of fish also attack and devour them when they approach sufficiently near the surface of water Though a number of mosquitoes can be destroyed in the adult state by such enemies It is probable that this loss is small compared to that caused by the natural enemies shich attack the insect in its larval state Amongst such natural enemies fish take the first place Un fortunately all fish do not eat mosquito larve but only certain species Amongst the fresh water fish that ert them are the following Anabas scandens Haplochilus lineatus, Polycanthus cupar nus Barbus stigmata, a species of the genus Ophiscephalus, and lacrones The sea water fish that are known to eat mosquito larve are the Therapon farbra and a species of the genus Mugil It is probable that there may be several other species of fish which feed on them Should any collection of water be met with where fish are present and mosquito larvæ absent it is worth while testing whether the fish eat them Put some of these fish in a suitable glass vase and put some larve with them and watch the result As some fish do not eat the larıæ as soon 7$ they see them it is best to observe the experiment for twenty four hours Where there is much weed and floating vegetation in the water mos quito larve take cover under them and defy the fish The use of fish as larval eaters opens out ·PREVENTIVE WORK 63 quito larva immense possibilities of successfully preventing breeding of mosquitoes in permanent collections of water especially where there is no vegetation There is no casier method of dealing with the pest Certain aquatic insects such as water boatmen and some beetles and bugs also destroy mos Some plants such as that which is commonly known as the rootless duckweed are also said to be their natural enemies The successful use of these natural enemies is a matter of individual discretion on the part of the person carrying out mosquito destruction The Artificial Enemies - The artificial enemies of mosquito larvæ are what are known as larvacides The most commonly used lorvacide is oil which by blocking the respiritory passages of the larve suffocate them herosene crude oil castor oil and gingelly oil are some of the oils that are generally employed either alone or in different combinations The most commonly used com bination is a mixture of equal parts of herosene and crude oil A mixture of crude oil and crude carbolic acid (20 per cent) in equal parts has proved highly satisfactory in our experience Various dışınfecting fluids such as Cresol Izal and Newcol are also highly larvacidal The employment of disinfectants as larvacides is depen dent on the correct strength of dilution of the dışınfectant An insufficient amount of disinfec ·64 PREVENTIVE WORK tant added to a collection of water will be far too dilute to be of any use as a larvacide Hence it is preferable to use a disinfecting fluid lihe Cresol or Izal in shallow collections of water, and oil in large collections where a continuous surface film wall suffocate the larve and will them Certuin chemicals such as sulphate of iron and sulphate of copper also destroy mosquito larve when added in proper strength to the water in which they are breeding but by far the best chemical we have come across Is 7 substance called Paris Green This is an arsenical compound and is diluted in one part in 100 parts of fine cork or road dust and streun over the surface of water where larvæ are to be found This can be usefully employed in large collections of impound ed water such as tanks and ponds where the use of oil or any other larvacide will be far too expensive to be practicable In order to be able to detect breeding in col lections of water every inspector should by practical personal experience be thoroughly con versant with the methods described below Mere book knowledge in this very important section of his work is entirely useless He should provide himself with a white enamel dish (10 in x 8 in )an ordinary table spoon an ordinary bath tin a hand net und a well jarval net A well net consists of muslın spread loosely over a loop of iron wire ·PREVENTIVE WORK 6 about 13 in in diameter To the loop are attached three chuns about 2 ft in length which in turn are secured to a small ring above To the small ring a suitable rope is tied so that the net can be lowered to any required depth 1 hund net consists of a similar net of smaller dimensions attached to a handle Armed with these imple ments the searcher should observe crrefully the surface of small shallos collections of water which have been in existence for some time If lary z Tre present tiny ripples are crused on the surface of the water by their movements and they can actually be seen swimming about or resting near the edges of the pools with the tail touching the edge and head facing the centre there are any floating weeds in the water larva may be found clinging to the weeds It my so happen that at the time when a pool is inspected all the ları y may be resting at the bottom and none will be seen at the surface It must not be concluded that the pool is free from lurer By stir ring up the water vigorously suith the spoon and examining the surface again larse of present wall be made clearly visible 15 zinst the muddy water Where the surface of the water is covered with fegetation what is known as the dipping method should be tried Bi means of the bath tin the water from as close to the segetation as possible is transferred along with any segetation to the ·66 PREVENTIVE STORE enamel dish The water is allowed to remuin a few seconds in the dish when larve of present will be seen coming up to the surface By far the best way of searching a pool is by using the hand net and the method employed is to fill about half of the enamel dish with water free from ları 2 and put the net in several places in the pool and search round first at the surface then at the edges and finally deep in the pool Care should be taken not to allow the larvæ caught in the net to escape The net is then withdrawn and inverted into the enamel dish when larvæ if present will be seen in the clear water The operation should be repeated several times be fore a pool is pronounced free from larve For wells water cisterns etc, where any of the above methods will not be satisfactory the well net is used by lowering it at several spots into the water and inverting it into the dish containing clear water If larvæ are present they can be seen in the dish Larvæ have been known to thrive in all sorts of water collections from the freshest rain water to pure sea water from the tiniest collections of water between the axils of the leaves of certain plants to large ponds swimps and rivers There fore no water must be ignored but each collection should be systematically searched and experience will show in what surprisingly odd places mosqui toes all breed ·PREVENTIVE HOP 67 on the wing The Imago or adult mosquito can be captured in one of twoways Either search can be made for him in his resting place or else he may be crusht In the former case the wpparatus required will consist of specimen tubes and cotton Wool with which to plug the ends of the tubes Having carefully observed the mosquito resting on a wall in a cupboard or on clothes the pledget ci rool is removed from the end of the specimen tubes hich is passed carefully but slowly over the mosquito ud then the pledget of cotton wool is slipped underneath the tube so us to block the entrance If the cotton wool is pushed holt donn another mosquito may be raptured in the sine tube if desired When mosquitoes are flying about a hind net fashioned lihe a butterfly net is required in addition to the glass tube The net is passed over the flying mosquito by a sni ceping movement and the exit is immediately closed by gripping the outside of the net near the entrance with the free hand With little mani pulation mosquitoes caught in this way can be passed into tubes and secured by 1 cotton wool prug as has already been described Should the opecimens only Le required for mounting it will not be necessary to catch them in a tube simply place come chloroform on 1 pledgct of cotton wool inside the nct and all the specimens will be dead in a few minutes and they will be rends for mounting 6 ·68 PREVENTIVE VOR A most thorough inspection must be undertaken before any building can be pronounced free of adult mosquitoes In Indian villages all huts must be carefully examined The thatch of these huts is a favourite resting place and very often the colour of the thatch coincides with that of the mosquito and it requires careful searching for their detection In almost every house in an Indian village a huge bashet in u hich grain is stored, will be discovered in one corner The inside of the basket is smeared with cow dung which gives it a dull grey appearance There appears to be some curious attraction for mosquitoes there and usual ly large numbers can be discovered resting in these bashets Adults should be destroyed wherever possible but unfortunately no satisfac tory trip has been devised that will attract them in really large numbers Sevenl situations may be mentioned where mosquitoes are likely to be found and among them ire to be noted all cow sheds and outhouses under the enves of huts and in dark corners of houses especially on any cobwebs discovered there Mosquitoes have a curious fancy for dark ind grey clothes and for the inside of leather boots and the under surface of saddles IVhat the attraction is has not been satisfactorily explained Some authorities think that the colour is the attraction, while others suggest that the odour of certain articles for ·PREVENTIVE WORK 69 example boots is what they like Basements and cellars are likely places to find the Inago and in certuin countries they have been known to hiber nate in them throughout the cold weather The uses to which an adult catch can be put besides the attempted reduction in total numbers are the identification of species in a gien urea the regis tration of houses burracks and so on where the largest numbers can be crught and at what periods of the year each species is most abundant But there is a much more important observation to be made from such 7 catch Large numbers of Anopheline thus caught ire dissected with a vien to determining what species carry the plasmodia of malari and which of these species are the chief culprits Haung determined these facts and knowing the habits of the species in solved we can locate their breeding places and make anti mosquito plans In cirrying through such 7 scheme there are several points which must be carefully observed It must be remembered that inti mosquito cum pugns involve expenditure and unless adequate Provision is made in the beginning to incur such expenditure such schemes will only end in discredit to the personnel concerned Hall herrted mersures are worse than useless and ar more 1 pretence than in cinest attempt at prei ention of malaria ·70 PREVENTIVE WORK An antı mosquito campaign once started can never cease just as much as conservancy arrangements cannot cease and must go on indefi nitely We cannot hope to exterminate mosquitoes once and for ever until we reach 1 state of civilization much higher than the present In the meanwhile war against mosquitoes has got to be continued without abatement and then only shall we succeed in reducing their numbers to any appreciable extent The officer entrusted with the conduct of the campaign should be made solely responsible for it Undıvıded responsi bility in anti malarial operations is an asset the value of which cannot be lightly ignored Where different parties are concerned in a particular locality and unification of responsibility cannot for various reasons be attained a committee composed of the representatives of the different parties should be formed and thus ensure the closest co operation of all concerned One cannot too strongly emphasize the importance of selecting the personnel Every endeat our should be made to get the right sort from the chief officer doun to the men of the antı mosquito gang on the intelligence and honesty fo these much of the success or failure of a scheme will depend The officer should not be hampered by too much office work and by other duties but should have ample time for outdoor personal ·71 PRET EVTIVE WORK work to check the duties of those working under him The subordinate staff should be well trained in i knowledge of mosquitoes their life history and habits they should know how to detect the presence of larvæ how to hatch them out and mount them, how to make an adult ratch and even to be able to recognize the commoner kinds of Anophelint in the locality Inti malarial schemes should be backed up by proper legis lation though this might be used as a last resource Owing to the inadequacy of punishment given by legislators for sanitary contraventions some wulful and recalcitrant people would rather under go the punishment than ubev sanitary rules Deterrent punishments and the disallowing of endless petitions will soon put a stop to this The returl anti mosquito cimprign may be broadly divided into major and minor works Afgjor works such as large drunnge schemes dnerting streams and channels or filling up inrge su imps will usually require a considerable capital outlay in addition to the recurring expenditure for their upheep Whether it will be more econo mical to do the major works or minnr works in the first instance should be decided at a very etris stage of the compugn in consultation with the engineers taking into due consideration the species of Ino Nichm present their hnou n habits and the conditions under which they art found ·72 PREVENTIE NORK in any particular locality Engineering skill exhibited in ignorance or in defiance of the knowledge of local Anophelınz often ends in ex penditure thout any resulting benefit Under the heading of minor works we include such measures as systematic inspections and the use of larvacides draining or filling up of casual water collections rendering wells and water cisterns mosquito proof by screening then, filling up tree holes and so on The area to be controlled is divided into six sections corresponding to six working days of the week and one section is dealt with on each day By the end of the week the whole area is covered and the following week the process is repeated and the different sections are inspected in the same order Each such area is entrusted to one inspector who will have a certain number of men working under him, depending on the nature of the work to be done If it is a large tract of country that is being controlled there will naturally be several such areas cach under an inspector The advantages of visiting the sections in a particular order are that there is less chance of omitting ny section if such a routine method is followed and the inhabitants, if any, of that particular section know exactly when to expect the visit of the anti mosquito squad During these inspections all possible breeding

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·MOSQUITO PROOF
A well w th cennetd me
A NO QUITO PROOF TANK
O rtl w pipe
ered wth wi
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oli tolp mt dat
w tht k
C biti gid to mh 1

·PRFI ENTIVE WORK 73 places are carefully looked for and dealt with as described The inspector who always carries with him a notebook and pencil will carefully note down such places as he finds breeding and he will the samples of all larve For this pur pose he will have with him several numbered glass bottles and in these larve will be sent back to the laboratory for identification He will note such permanent places as wells cesspits and water cisterns where he discovers larve and report the fact to the officer in charge of his area There are however many occasions where the breeding can be dealt with on the spot It is then usually occurring in temporary breeding places He will order his squad to spray oil on a cesspit to drain 2123 casual water or to till up 7 puddle with earth He sees that all barrels or fins are emptied of any water they contain The barrels he has turned upside down and old tins and odds and ends are col lected for disposal by the sweepers concerned The permanent breeding places are dealt with in rious ways The squad should clear up drains and water channels freeing them from rubbish and undergrowth It breeding is found in them they are sprayed freels with oil Water channels should be emptied of water at least once 7 week and the channels clerned out in order to prevent water from accumulating in holes in such ·74 PREVENTIVE WORK channels they should be constructed of cement or the water should be laid on in pipes It must be carefully noted that when oil or Cresol or any other such larvacide is used a very essential part of the procedure will be the employment of a coolie to walk behind the person spraying the oil He will intimately mix the water and larvacide by vigorously stirring up the water with a Sileepers broom This is of the utmost impor tance if good results are to come from the use of larvacides Garden tanks for holding water, with which the malı waters the garden can be dealt with in various ways but the first essential is that it must never, in s hole or in part be below the surface of the ground If it is then it cannot be properly emptied and if it is not emptied it is sure to breed The best type of tank is one built of masonry above ground Its dimensions are of little importance but one thing is essential namely the provision of an outlet pipe provided with a tap placed low down so as to drain the tank On his round every week the inspector must see all these tanks empty or else empty them himself The householders will readily agree to see that the tank is emptied each evening by the male and that there is no water in it on the day of the inspection The substitution of hosepipes for tanks should be encouraged as much as possible Ornamental fountains are the scourge of the ·PREVTVTISE WORL 75 inspector but the addition of those fish which are the natural enemies of mosquito larve will usually stop any breeding occtirring in them House holders should be warned of the necessity of leed ing those fish and the inspector will make ? point of seeing that they are alive and sufficiently numerous on his weekly round He should replenish them as may be necessary The fountains should be hept clear of water lilies and other vegetation which will proude protection for larve Where a Ind-on water supply exists i cement platform should be built under cach stund pipe The edge should be raised about six inches and the water top should overhang thi trough The trough should be druned by n properly con structed drain with ? qully trip The drun should be connected with the general draine system where such exists or should lend to a properly constructed soilige pit No puddles should be permitted to exist ner i stand pipe This gully trap is inspected and oiled every sech 1) a routine mersure Cisterns are usually prouided for each bungalos or group of bung? lous where there is laid-on water it is to be found either under the rifters of the roof or raised on a platform to the requisite height in These tanks should recente Special care and should be rendered mosquita the compound ·76 PREVENTIVE WORK fitting lid proof There are aludys two and sometimes three openings through which the Imago may gain entrance There is the manhole, this should be provided with a properly which is hept padlocked If necessary the edges of the lid may be cemented over so that no space can be left between the lid and the tank The overflow pipe must be provided with wire gauze over the outlet so that no female mosquito can gain entrance by it A third entrance may be discovered where the inflow of water takes place This pipe should be bolted to the upper edge of one side of the tank but sometimes it is thrust through a hole in the top When this is so cement should block up the gap betueen the pipe and the lid All tanks not mosquito proof will be reported on by the inspector Wells mas present great difficulty in India where they are in common use In Colaba they have now been completely covered over by dome shaped masonry work This is a cheap and efficacious method and has much to commend it The well cannot be opened as the lid of the man hole is bolted down and the dome presents either water or rubbish collecting on top of the cover Wells have usually a semi religious and semi magic significance attached to them and the complete closing of a well used for drinking purposes is objected to because fresh air and ·77 IREVENTISE WORK light cannot gain admittance to the siter This difficulty may be overcome by rusing the sides of the well some six or eight feet high and roofing it with wire gauze The water is withdrawn from the well by some form of hand pump similar to that employed in England Wells which are used for the provision of water for irrigating land present a much more acute problem and the best suggestion we can offer is the covering of the well and the provision of an internal combustion engine geared to 1 centrifugal pump R hatcver solu tion there may be to this problem one fact from an anti mosquito point of view must not be lost sight of and that is that wells in india re the permanent breeding grounds of the sphense which is n notorious carrier of the parasites of maluri and it antı mosquito mesures are to be successful such wells as breed this insect must be rendered mosquito proof During their weekly inspection it is the duty of the inti mosquito gang to inspect the water seals of wash-down water closets Those not in duls use should be oiled and 7 film of oil should be prend over the surface of the water in the cisterns above them Vessels containing water inside houses should be emptied duly Amongst them are not to be Le overlooked flower vases and challe Instead of water in antifornucas we would recommend cresol or if the smell is objected to oil They ·78 PREVENTIVE WORL are quite is efficacious in presenting ants swarm ing up on to tables or into meat safes and they do not breed mosquitoes They have the additional advantage of requiring very little attention One of the most constant casual breeding places is the run water gutter which is very often found on buildings in India During runs these become choked with dirt and grow weeds Thus water collects in little pools in them No building in India should have a run gutter The water should run directly off the roof to fill on ? cement ledge on the ground level The outside edge of this ledge should have a channel to lend away the water Where there are flat roofs water often lies about on them during the rains This water should be brushed off at least once in ten days All gully traps connected with a drunage system must be oiled and if a cesspit be found in the courtyard of 7 house this must be in spected to see that it is properly constructed and rendered mosquito proof All inspection cham bers should be inspected to see that the covers fit properly and if they do not then they must be opened and searched for mosquito larve De fective covers are reported on by the inspector The handlegrips in the lids of manholes and other such covers are cup shaped depressions crossed by 1 bar of iron These depressions ·PRET ENTIT E HORA 79 constantly become filled with rain water and form common tempomrs breeding places They should be filled with earth or cement Gardens especially untidy ones require the attention of the inspector Undergrouth and long Grass should be forbuden ingu here near humın hab tations They provide excellent shade for the Imago during the day and concenl all sorts of rubbish capable of holding water Certain plants collect and store water at the junction of the stem with the leaf The tiger lily commonly seen in Indiin gardens is such a plant we frequently have found it breedin, mosquitoes Such plants should not be grown in garden Trees in the area under control should be inspected carefully once a year and all hollows in them tilled with a mixture of one part cement to two parts sand When the holes are very large they are partially filled with stones and then coured with cement Very seldom is it necessary to cut down tree 411 trees inspected should be marked with a white cross while such trucs 25 are tound breeding should be indicated in addition with red cross On the dai preceding the inspertion of 7 section onemn is detuled to go round and collect all tins and odds and ends lying about Ile deposits them so that they can be rumoid by the scaven Surs on their rounds ile also hands in at ench bi rcalon 3 questionnaire cird dippendir !!)

·80 PREVENTIVE WORK on which the occupant is asked to state whether he is troubled with mosquitoes or not This card is dated and initialled It is returned to the inspector when he calls next day on his inspection These cards were started in Colabı with a view to finding out where mosquitoes were most trouble some One surprising result has been the regu larity with which they have been filled up by civilian and military inhabitants There is no compulsion about these cards and the housewife has on many occasions asked after her card should she not have received one They usually give the first indication of any outbreak of mosquitoes It is also a rough and ready guide to the inspector of the progress of his work and informs him to what sections he should give special attention IE he is unable to detect any breeding place there he reports accordingly to his officer who takes the matter up and this particular area his careful attention In a large majority of cases where com plaints are made about mosquitoes breeding can be detected in the immediate surroundings The inspector returning from his rounds will that day enter all records made in his notebook in the book at the office provided for that purpose Each section of an area has a book and under the date of the inspection he will enter the exact position of any breeding places discovered the nature of the water where gives ·PREVENTIL P WORL 61 found breeding for eximpie a tin in the mpound a weli a cistern or a brackish water al as the case may be Vlatters he has noticed quiring attention beyond his power to correct 1 be entered up for the information of the cer in charge who will take such action as he y deem expedient expedient The inspector also intrins a chart ( ide Appendix V) which shows : division of the nrea into sections and the Son which each section is visited This art will be kept up to date pot map maintained for each section concerned and enever breeding is detected it indicated by listinctive spot according as to whether the 12 are of the genus inophiles Culei or Shego Such methods ? the above lend to itematır Kork on the part of the inspectors and id to zvoid confusion which wuld be disastrous the ends in view The progress of an anti mosquito rimprio'n istered by the incidence of malarız occurring hospitals and dispensaries more #curite imation of the amount of moril in 1 filen trict in shown by the incidence among the Idren of that area betu cen the ages of two and 1 years One of the symptoms of malır11 is in larged spleen and children of these tender irs are very susceptible to the disease and en they are attached by it their spleens become ·> IREI ENTI E MORK enli med ind so long as they suffer from it ulur y sunetuines reaching an enormous sia I hit duition in the percentage of children with lingua pieen is a sure indication that a cam pun in progressing favourably from rather complirited (alculations a figure is arrued at which is called the Splenic Index This index shows the prevalence of maların in a district In conclusion we would dras attention to the subject of proprg indwork by which the interes of the general public nin be aroused Although it is not bhely to be effectue by itselt jet it might here and there appeal to the more intelligent *ho would press for greater co operation between the public and sanitary ruthorities While anti mosquito measures must always be supported by public opinion yet it is the duty of all who kne Inon ledge of the ravages of malaria to educate and arouse that opinion until we reich such ? stage of civilization that we all look upon the mosquito ?s ? noxious insect not to be tolernted in our midst In the same way as we look back ? fex generations and wonder with disgust hor our respected ancestors ever permitted themselves to be the hosts of loathsome bodily parisites so us!! future generations be astonished it the many maheshift and ineffccturi measures that we adopt to day to void milırja and yet allow mosquitoes to dwell in our habitations

·BIBLIOGRAPHY
7
1 STEPHENS AND CHRISTOPHERS TI
of Malaria and Bloo i parasite
9 JAMES AND LISTON The door!
of India
3 PATTON AND CRAGG Tert bool 21
+ ALCOCK Entomology for Medical C
SEH Ross heduction of Domesh 11
6 SIR VALCOLM WATSON Prezentı
the Federated Walay States
7 CASTELLANI AND CHALVERS
Medicine
8 VANSON Tropical Medicine
9 SIR RONALD Ross Prezention of V.
10 Tice Practice of He licine
1
JOURNALS AND REPOKT'S
I Indian Journal of Vedical Research
Indian Aledical Research Vemour No ? mier
1994 COLONEL S R CHRISTOPHERS IMS
3 Indian Medical Ga ette
+ Bulletins of the United States Public Health Serie
Ceylon Journal of Science
f heport on the Inzestigation into the Cruses of
Malaria in Bomba; DR CHARLES A BENTLEY

·82 PREVENTIVE WORK enlarged and so long as they suffer from it remain so sometimes reiching an enormous size The reduction in the percentage of children with un enlarged spleen is a sure indication that a cam paign is progressing favourably From rather complicated calculations a figure is arrived at which is called the 'Splenic Index This inder shows the prevalence of malaria in 2 district In conclusion we would draw attention to the subject of propaganda work by which the interest of the general public may be rroused Although it is not likely to be effective by itself yet it might here and there appeal to the more intelligent who would press for greater co operation between the public and sanitary ruthorities While inti mosquito measures must als zys be supported by public opinion yet it is the duty of all who have knon ledge of the ravages of maları1 to educate and trouse that opinion until we reach such ? stage of civilization that we will look upon the mosquito as a noxious insect not to be tolerated in our midst In the same way as we look bach a few generations and wonder with disgust hou our respected ancestors ever permitted themselves to be the hosts of loathsome bodily parasites, so will future generations be astonished at the many makeshift and ineffectual measures that we adopt to day to avoid malaria and yet allow mosquitoes to dwell in our habitations

·BIBLIOGRAPHY
1 STEPHENS AND CHRISTOPHERS
Th /
of Malaria and Blood Dvasite
? JABLES AND LISTON The not/
of India
3 PATTON AND CRAGG Peito oh itu
+ ALCOCK Entomology for Medic (11
SEH Ross heduction of Domes :
6 Six MALCOLI WATSON Prenti
the Felerated Valay States
7 CASTELLANI AND CHALVERS v
Medicine
VANSON Tropical Vedicine
9 SIR RONALD Ross Pre entron of !
10 TICE Practice of ledicine
2
JOURNALS AND RETOI TS
1 Indian Journal of Medical Rescarch
Indian Medical Research Vemoir NO
(cmhe
19?4 COLOVELS R CHRISTOPHEES IV
3 Indian Medical Ga elle
Bulletins of the Umled States Public Health
Ceylon Journal of Saence
6 Report on the Inzestigation into the (nrses of
Malarra in Bombay Dr CHARLES A BENTLEY
10

1No text on this page.

·APPENDIXES S

·No text on this page.

·APPENDITI 87 APPENDIX I HOW TO SEND LARVE AND LARI AL SKINS FOR PURPOSE OF IDENTIFICATION AND DESCRIPTION FULL GROUN larvæ are isolated by placing them in tubes Only one larva should be placed in each tube When pupation takes place the ları al skin 15 cat in the water complete with all the hairs and chitinous parts the skin 18 carefully poured off with a little water into a clean petri dish the pupa being left in the riginal tube with some water The skin is carefully lifted from the water by means of a small slıp of filter paper and transferred to a small tube containing a mixture of t3malın and water (about 10 per cent forman) This small tuhe centaung the skin is numbered by placing a number on a small slip of paper in the top of the tube a similar number on another slip is put in the top of the tube containing the pupa being held in place by a plug of cotton noul this plug also series to prevent the escape of the mosouto shen it emerges Wheri emergence has taken place the mosquito is transferred to a clean tabe by holding the latter with its mouth to that of the former tube after removing the plug The plug is then pushed into the mouth of the tube containing the mosquito and a few drops of chloroform poured upon it the mosquito is then mounted in the usual way and a small label attached to the pin corresponding to the number of the larval skin from which this mosquito resulted The mosquitoes and the skins can be sent in their respectie tubes by post. The small tubes containing liquid should be filled up to the cork and if possible sealed wsth wax by dipping the top of each tube into melted was ·88 APPENDIL II APPENDIS II HOW TO MOUNT AND PRESERVE MOSQUITOES APPARATUS REQUITED 1 Speamen tubes with corks ? Fine double pointed nickel pins No 3 3 Cork sheets + Cardboard Ş Forceps tith grwpied teeth at the tsp First prepare your specimen tubes as follons Paste a hite paper on to a cork sheet and cut it to small strips just brond enough to go inside the specimen tubes Athch 7 strip to the cork of the specimen tube by passing an orduary pin on esther side from the strip to the cota The cork strip when thus fired to the cork of the tube should not louch the bottom of the tube but just clear Mahe a small triangular slit on one side of the cork of the specimen tube so that a small grooie exists between the cork and the glass and into this groote fix a pledget of cotton wool The tube is now ready for receiving the specimen Place the mosquito upon its back on the end bnard Hold the pin about the middle with the forceps and push one end steadily through the thorax so that it just emerges from the centre of the dorsum of the thorax The mosquito is nou transfixed to one end of the pin ift the pin and transfix the other end to the cork strip of the prepared specunen tube In this 11 ay about ten mosquitoes can be mounted and preseri ed in cach tube fut & len drops of pure carbolic acid on the cotton 1100) plug Put carbole neid on the plug once 1 month and this all present the specimeas getting moulds ·AI PENDI\ III 89 APPENDIX III HOW TO HATCH OUT MOSQUITOES FROV LARIE PLACE the larvæ in a white enamelled basin contaming some of the water en Which they were found keep them there till they beconie pupe when they should be removed from the basın to side mouthed glass butties filled three fourths with water and over the neck of which a piece of mosquito-netting is tied The mosquito netting retains the emerging adults PY ·90 APPENDIT IV APPENDII IV HOW TO MAKE A CLEAR AND PERYA EMT PREPARATION OF LARVE METHOD I Put the laiva in a test tube and pour a fer drops of crustic potash or soda (2 to 5 per cent ) solution in natur Boil for a few minutes when clea transfer the whole into a watch glass pour off potash solution wash in distilled water two or three times Then transfer the laria to 50 pei cent alcohol heep for five minutes then transfer it to 70 per cent alcohol heep there for 5 or 10 minutes then transfer to absolute alcohol and keep for 15 to 30 minutes During all these processes never allow specimen to get dry It is better to change the absolute alcohol two or three times From absolute alcohol place it in a drop or two of clove oil till it is sufficiently clear (about 5 to 10 minutes) when clear remove with a pin or brush to a slide and put a drop of Canada balsam over it and with neelles manipulate the position in which you want the larva then coier uith a cover slip METHOD II Put the laria in a watch glass containing 10 per cent formnalın Il len dead transfer it to another match glass containing alsolute alcohol so as to dehydrate it then transfer it to close oil or oil of wintergreen and when clear mount in balsam Tuso strips of cardboard placed under the cover glass will support it ·ATE Aror F Ar 1) ATC Are, 15 ArenA Sunday W na Tuestay Wednesd Thursday Flas >ເardວງ Vunday Tuesday Wedond) Thursday Prida; Stura v Sunday al riday Tuesday Rednesday Ti ursulay Friday turday Sunday Monday 1uesias Wexfnesday l'hursday nday Saturlay DAILY DAITE I OUTINT OF ANTI MAI ARIAL WORL FOR THE MONTH OH 192 16 APPENDI V ·92 APPENDIT VI APPENDIX VI QUESTIONNAIRE CARD Bungalow No Occupants Name } Are You Troubled by Hesquitoes? On presentation of this card please state es or No and sign your name Date Yes No Signature ·43 APPE NDIY VII APPENDIX VII TABLE FOR IDENTIFYING THE FEMALES OF THE ANOPHELINES OF IVDI 4 18 - Always make certasu that the sperimen examined is a female din pheline Sperial att no o is dugupt the tes at the end of the table I WINGS LNSPOTTED A DISTINCT WINTE I e SPOTS #7 DiSTAL ENDS OP HID EFYORA (Voimg 7) A plumb var brianen B NO DEFINITE h 18F SPOTS 1 Head scales very narro: lnear Palps per thin Antenor feshed cell nearly double px sterior (Mate 7) A 2 Head scales expanded 18 in ordinary Anopheles Palps not very thin Anterkt forked ol re Jatusely shorter (vo e 7) A cul fom.

·94 APPENDIU VII II WINGS SPOTTED A TIPS OF HIND LEGS \\ HITE (If not white see p 96 ) 1 Femora and Tibiae not Speckled (Note 1) (If speckled see p 95 ) a At least the two termmal tarsal segments of the hind legs completely white (Notes 2 and 7) (1) Dor um of abdomen heavily clother with pale scales projecting at the ides to form tufts on all egments A pulcherrimus (11) Dorsum of abdomen not so clothed no lateral scale tutts Fifth zein ef uing pale in the greater part of it's eitent (Wole 7) Ventral aspect of most of the abdominal seg ments with scattered pale scales ristal end of first hind tarsal segment never picked out with white (Note 7) A pall dus Ventral aspet of abdominal segments pt so Distal end of tirst hind arsal segment van able u ually piched out with white (Note 7) A. ph / ppinene. Fifth zein of uing moslly dark Distil end ol first hind farsal segment conspicuously picked or twith a hite (Note 7) Á ful & nonu b Onls the terminal hind tarsal segment completely Khite (Notes 2 and 3) Four «hite bands on each pulp including apical band (Note 7) A karwari ·APPENDIT III 95 2 one parr om di) רוחו A Femora and Tibiae Speckled (Note 1) (If not speckled see p 91) a Two or three terminal tarsal segments of hind legs complclely bite (Notes and ) (1) Fach palp rith b dp! til od od prin loint 7) Thice ter nal hil nis pletchle (Totes Pips pror! rently so ckl di Ite) Amclp lp.1Indn ter 11111 compl tels hotell!: ad htc baid 6 ellis Pilns I spend te Ath bald (11) Each palpith ne bripl p1 xl band and to ouro mr prn1 b Less than two terminal 1 al seguents hund legs completely white ( te and /) 6) Each palpith f ! rh stol in Uudi s piiblit 521 Te darh Al 1 Leluff & SA I ICH 12v ze! Isrfe Hll of te ulitel le 7) Ako h 1 742 of 1 ! at 1/ s / SchcX/III/7 lit #hip III rolly от ри le) } Alu ophytu rbo-ars ! t f 11 11 th ut or du! At latu (11) f ch palp with three pi band Pal baod (lote 51) DYS 11 of wol of te od I seks els tht kly cltled aith scales A w Ilmon Scales of present estricted to the last feu abdu) 11 I segi ints A maculatus 2 1 lud ·96 APPENDI VII B TIPS OF HIND LEGS Nor WHITE 1 Femora and Tibiae not Speckled (Note 1) (It speckled see p 98 ) a Less than four dark areas on costa intol 1916 both the costa and the (1rst longitudinal 101N of uing (Note 7) (1) Inder half of co ta without any distract pale ipter ruption (Note 7) Brord .white band on femur of kind leg With prominent scale tuft associated with the band Aann ndale Without such a tuit A linde a No broad uhite band on femur of hind leg Palps with some pale bands A hy canus var niger mus Palps with no pale band Hith prominent scale fuft on zentral surface of ezenth abdominal segment A barbiro trio Hith no such scale tuft A umbrosu (11) Inder half of co ta with pre interruption (Note 7) A&R b Al lcast four day k areas on costa rnzol ing both the costa and the first longitudinal ein of ding (Note 7) (1) Fr ot tarsal ft ints with broad pale bands (Note 7) (If without see p 97 ) Palps with dark pre apical area equal to or nearly equal to pale apical band (Note 7) Aubp ctus (ro 11) Palps with dark pre apical area half or less than half the length of the pale apical band (No e 7) A varus ·APPENDII VII 97 (11) Front tarsal juicts without brod pale band (If with spe p 90 ) Tips of palds black Dorum of thorax with hair or otro false scales Sixth wing 10 vithery ind fin le mar, pgs (Note 7) A turkhud, Dorsum of thor ith obslous ue xales Sath wing en hery def o te parking (three dark spots) (Note 7) A mult ol Tips of palps not black Third longitudinal i ing ein dark (NE no pale spots on ut g zeins ofker da. those v coste (Aote 7) Ahode en Pile spots prese i on other te s A cul fa Thinh longst do ) og 10 bght (7) Euch pilp? th luo aliwow equ?/ bro do disti bands and a spille 71 Pre Buscus pal in ap I hf Sehing with tt dark pot (M + 7) A A Ont. Ir bosci tots Sixth Den tht to dark spx (N) Ama mus 'Palds not so Ion rau rte fca wat! p 1 int rupti (Note 7) S les presentanth strem front et d rumf thr Alton Inner 4 13 ter ft ith pul errupti (te). S ales penent er rust ct lors mith rux Longest pole. sta less th halt de la iglk of longest du hi ca !!7) Ta st of had leps ust rlly rrowly 1 dish clly brz dedu ih uhle A 1 yponien Loigest pala a osla zer I flesh ter thin Ingest da 1 (ole Irs of 1 ud legs not o ided Us A superp tu ei ·98 APPENDI VII 2 Femori and Tibiae Speckled (Note 1) (If not speckled see p 96 ) a Each palp with four well in thed pale bands including apical band (Notes 5 and 7) (1) ?idio tarsal joint of hind leg broadly and con picu ousls banded with white A leucosphorus (11) Tıb:o-tarsal joint of hind leg without sich broad band A ! selatus b Each palp with three sell marked pale bands including apical band (oles and 7) (1) Each palp vith tuo broad distal ap 1 one narrow pr timal band (Note 7) alps spelled (Note 4) A stephen (11) Each palp with one broad apical and two Darrov more proximal band (Vote 7). Palpot speckled (Note 4) A. ludlow 1 ·re APPENDIX VII 99 NOTES TO PRECEDING TABLE le 1 Afunt motting, at con della spe kl & Seen nler the mir scope the pots ont tut g pehl gare ilu clearly defined areas fp i se! Tarsal segit ots complelely wh te ar 1 ted frm th tip of the leg stopping of the f rsd * 677 Ile 3 In th case there a tally ht fmo & tant h gher up he tarsi Sale Speckling on the o lps r fers t sh te put their drsal urface v ually b tu een th o ddle and p m 1 pale bands Ale 5 Rzase of speckl & Ilitoa th band te 6 Spe les entered in more th pla in th tabl may hus metimes be app aran od metim an thr or an appe rance hh may he el hed In eithr case the table will kr rrectly 1 The f rsl t rsal seg ent that nearett tb tiba Te mtnil segments are threat th tp of th 1x Hi d firsıl segments t the e fhip 11 Front lars I seg ents t th ff nt leme By apical band meant 1 lite imtp Distal means si uat d furthest from th byly Porin I means it ated re to th The est: is the anteri bod of the w og The first longitud: al z prit1 th cuta Th seco a long ! dnlren les heh a th first ad dy is nt to pran hes Th th d longit d n I reth s behind th cad and 1 upbranch a The fourth I ngult d nila ni hehind the third aan divides into t o br a hes The f fth lo gitudinal eta 1 beh d the forth and d des fatot vo b an 1 The sixth longit du i en lie beh od the fifth nd unbranched The anterto forted cells th Pit th wing log betyse the branche of the ec ad lo gitudinal The posterior fo ked cell he part f the wing 13 10 between the braq hes fth forth l ng tud dalen Cent ! Mla Id 1926 B ·INDEL 13 Comted) Abdomen of Mosqmto 29 culicifactes A 51 97 aconitus 97 culciforms 51 93 ailkent d 31 51 93 Culicince defined 10 Alcohol 90 Culicini 10 31 Anal papillæ of laria 16 17 Curied Scales 29 Tunindalet d 96 Anopheles genus 11 et ser spe D cies of 11 34 51 93 Dengue 8 Anophelint breeding places of Dipter 9 30 46 51 capture of 38 67 68 Dia Jarva 22 defined 31 external anatomy 26 et see 17 15 et seq. E Jarva antenne 20 lana pal Fgg of cinoghelt 13 14 mate hairs 18 lan stigmata Culer 13 14 drik: 13 of 15 nympha of 24 ovum A turkhudi 13 Slegowa of 13 species that transmit maları? 51 el seg Ephemera 21 Antenna of lan e 19 of mos Ephemeru lane » quitoes IO 76 Apparatus 67 SS F i riki d 13 Familes 10 Filansis 8 B Fint Scales 29 burbirostris A 51 96 fuliginosus A $9 94 orrianensis d 51 93 Penigo lertian 5 G Plood Stream 5 6 Genera 10 818 25 d 52 96 с Chironomide 30 H Chiroi omus larva 21 Hibernation of Mosqu oes 50 Chitin 23 hyrcinus 7 52 96 Clypeus 19 26 Corethra Tury'e 23 Costal Spots 31 Indiensis 4 95 Crescents 7 Insecta 9 Cross veids 29 Ctler egg of 1? laria of 18 J 20 nymph of 21 Jamesu d 52 95 Culi idc defined 10 103 portens15 d 59 97 ·INDE 101 M 110 caron A 53 94 Loudfry 40 41 lubrum of 27 koch! A 53 95 leg of length of 1 fe of So Inte bistory of 9 maxillary palp L f 27 fetamorphos 14 Labor of Mosqi sto 27 muth parts of 26 prosie of Lanacides 63 5 6 30 cutetiamn of 27 Lati abctora a af 15 ay to hrt n out 89 t boust papillx of 16 17 antenst of and present by wing of 27 19 atuficial edersies of 3 nitros A 97 clvpens of 19 head of 19 watumledemies of 6 Sipbon N fube 15 tho ax of 19 to make ugna 96 pensabent preparation t Nymphs of Ansskelin 13 24 send for de ficaton 87 of Cusle 23 24 Stego y 23 Anophelan 19 of Chrono 25 19 21 of Corethra 72 of Cix 20 of Dira 2 of 0 Epke xurce 22 of Ster >> Ordeu 20 stared station 21 um de ter Leg of Mosquito 20 ucolphir so 53 94 P Life hyst ty of malt al parasite 4 se * seg palldS A $494 Landern $3 9F Pere i es of Mahn 3 Y sfon 53 97 Periodicity of Walantat larasites ludio.cat A 53 98 6 DAHOD NONS - 91 Plasmod TD 33 M pium dens 54 93 naculatus a 54 35 Prabota 1 Morgu to $ 6 27 macul ARZDE 54 35 30 Malana enderoi 60 bist ry IT totoon 12 pirasites of 3 11 ntory Dil kern » A 55 94 parasites of 4 setseg pira sites per ty o 6 Decles Q of Aroprelist that tran mt Onartan 3 5 6 7 51 44 plam 100 x us nige 62 Survey 38 Wagtant tertia 5 6 R diaxir palpi of museu 2 Y golo 30 Red Lells 1 54 97 rhort SIASIS A55 37 abd 10 ! 24 alios of 50 entence of 6 s pture of ivpers of 19 Sab thn 18 2 defis tion of ses persat Sales 29 33 ! $0 Aght of Find of Seuteltu of Moaju to 27 41 kb of 39</s64 bytes Species 11 36 of 50 housut Rad Spleen in Blalaria ?

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