Notes on the mosquitoes of the United States

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Title:
Notes on the mosquitoes of the United States giving some account of their structure and biology : with remarks on remedies
Series Title:
Bulletin / U.S. Dept. of Agriculture. Division of Entomology ;
Physical Description:
70 p. : ill. ; 23 cm.
Language:
English
Creator:
Howard, L. O ( Leland Ossian ), 1857-1950
Publisher:
U.S. Dept. of Agriculture, Division of Entomology
Place of Publication:
Washington, D.C
Publication Date:

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Subjects / Keywords:
Mosquitoes -- United States   ( lcsh )
Genre:
federal government publication   ( marcgt )
non-fiction   ( marcgt )

Notes

Statement of Responsibility:
by L.O. Howard.

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Source Institution:
University of Florida
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All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029639489
oclc - 08084065
lccn - agr09002971
Classification:
lcc - QL536 .H86
System ID:
AA00018933:00001

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BULLETIN No. 25-NEW SERIES.
U. S. DEPARTMENT OF AGRICULTURE.
DIVISION OF ENTOMOLOGY.


NOTES


THE MOSQUITOES OF THE UNITED STATES:


GIVING SOME ACCOUNT OF THEIR STRUCTURE AND BIOLOGY.
WITH REMARKS ON REMEDIES.


BY


L. 0. HOWARD, PH. D.,
Entomologist.


WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1900.


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DI VISION OF ENTOMOLOGY.


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Entomologist: L. 0. Howard.
First Assistant Entomologist: C. L. Marlatt.
Assistant Entomologis.: Th. Pergande, F. H. Chittenden, Frank Benton.
Irnvestigators: E. A. Schwarz, D. W. Coquillett.
Assistants: R. S. Clifton, Nathan Banks, F. C. Pratt, Aug. Busck, Otto Hedma,
A. N. Caudell, J. Kotinsky.
Artist: Miss L. Sullivan.

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LETTER OF TRANSMITTAL.


U. S. DEPARTMENT OF AGRICULTURE,
DIVISION OF ENTOMOLOGY,
IWashington, D. ., July 24, 1900.
SIR: I have the honor to transmit herewith manuscript of a bulletin
on the mosquitoes of the United States, which gives some account of
their structure and biology and indicates the differences in all stages
of existence between the kinds of mosquitoes which have been shown
to transmit malaria and those which do not. It also treats of the sub-
ject of remedies in considerable detail. It has been written mainly
from the popular standpoint, although scientific details of structure
and classification have been inserted for the use of physicians engaged
in studying malaria. I recommend that it be published as Bulletin No.
25, New Series.
Respectfully, L. 0. HOWARD,
Entomologist.
Hon. JAMES WILSON,
Secreta/y of Agriculture.






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INTRODUIJION.


A number of articles and notes concerning mosquitoes have teen
published in different bulletins of thisI Division. The most extensive
was the leading article in Bulletin No. 4, New Series (-The Principal
Household Insects of the United States"), and constituted the larger
part of chapter 1, on "Mosquitoes and Fleas." In this treatment of
mosquitoes the complete life history of (ldexpunfieui.s was given, based
upon original observations made in the summer of 1895, and some gen-
eral remarks on the subject of other species were brought together.
Four pages were devoted to the subject of remedies, and the mosquitoes
of the country at large were tabulated, with such notes on geographical
distribution as could be brought together. The earlier notes pub-
lished by the Division, including those extracts from correspondence
and general notes which had been published in the seven volumes of
Insect Life, and the writer's two articles on the use of kerosene against
mosquito larve, were all digested in this bulletin, which was published
in the summer of 1896. Subsequent brief notes on remedies have been
published by the writer in miscellaneous bulletins of the Division and
in the Scientific American, and the life history of Anopihelo? qiadrirna-
culatus was described, in comparison with that of (lexpunqens, in a
short illustrated article in the Scientific American for July 7, 1900.
The writer first became interested in mosquitoes thirty years or
more ago, when as a boy he fished and collected insects in the marshes
at the head of Cayuga Lake, New York, and as early as 1867 had
experimented with the kerosene remedy against mosquito larvar in a
horse trough at Ithaca. In 1881 he discussed with Dr. A. F. A. King and
the late C. V. Riley the bearings of the theory, which Dr. King was
the first to bring forward in the United States, of the probable rela-
tion between mosquitoes and malaria, both Dr. Riley and the writer
contending, it must be confessed, that the arguments brought forward
by Dr. King in conversation were based upon coincidental observations,
and afforded no good proof of cause and effect.
The writer's practical demonstration in 1894 of the value of the
kerosene treatment as a practical large-scale remedy attracted consid-
S.. erable attention to the subject of remedies for mosquitoes, and many
large-scale experiments were made, some of them being successful to
a marked degree, as will be pointed out later in the section on rem-
edies. The services of the members of this office force were called
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into requisition on a number of occasions to determine actual
points in mosquito-infested regions, and interest in the subject A
ually increased until, during the past two or three years, the r...ardS..
of those medical men, whose names have since become so well know!!!!:,'
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in this connection, showed by exact methods that Dr. King's 6thory'
must no longer be considered a theory but a demonstrated fact. ,: ..
has resulted that the attention of the entire civilized world has .been.ii
drawn with vivid interest toward the whole mosquito question. Every
fact concerning mosquitoes becomes now of great potential importune.
The correspondence of this office on mosquitoes, owing largely to b!f:..::::::::^ `
publications, has become greatly increased. The writer has beeno :
invited to address scientific bodies and citizens' improvement amoch- ....... ...
tions on the subject of mosquito extermination, and in the spring of'
the present year lectured before the annual meeting of the Boyal
Society of Canada and before the section on theory and practice tof
medicine of the American Medical Association on the subject of the
biology of the mosquitoes of the genus Anopheles as contrasted with
that of the mosquitoes of the genus Culex. The demand for the pub-
lications of this Division on mosquito subjects has been so great that
it has been deemed desirable to bring together the published and
unpublished articles and notes in convenient reference form from the
standpoint of the United States only, and this has been done in the
present bulletin.
The writer is indebted to his assistants, Mr. D. W. Coquillett, for
determinations of the different mosquitoes discussed; Mr. F. C. Pratt,
for untiring efforts in the collection of material; Mr. August Buseck,
Mr. R. S. Clifton, and Mr. J. Kotinsky, for assistance in laboratory
experiments, and Miss L. Sullivan, for the preparation of the ilustra- ,
tions. Information and specimens derived from many correspondents
are acknowledged in the pages of the bulletin.
LO. H.


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CONTENTS.


Oh mosquitoes in general .................................................
Abundance of mosquitoes .........- ............------ ..----.--------.


Alaskan and other far-northern mosquitoes ....
Length of life of the adult mosquito ..........
Life history of mosquitoes in general ------......--...
Food of adult mosquitoes .--------------------
How far will mosquitoes fly? .------..---------
Carriage of mosquitoes by railway trains ----......
How long can the larvae live out of water?......
The number of species of mosquitoes-..........
Mosquitoes and malaria ---.........-.........--.-
Synoptic tables of the North American mosquitoes- -
Generic synopsis ----------------------
Genus Culex ....---------------------- -..


S(a) Recognized species ------ ---- --------
S (b) Unrecognized species --- ------- -- -- ---
Genus Anopheles..- ....----..- ....--- .--.--..............-- .----.
(a) Recognized species ------------------ ---
(b) Unrecognized species..---..--...----..---.........--..
Genus Psorophora................................................
Genus Megarhinus.-----------------------
Genus Aeies-.. ......------ .....------ --...------............ ....
The biology of Culex, with remarks on some of the species.........
Life history of Culex pungens ..........................................
Remarks on other species of Culex .-..-.-----------------. -...--.---...
The distribution of the species of Culex in the United States -...--....--
The biology of Anopheles, with general remarks..... ----..-...............
Life history of Anopheles quadrimacihl us ...............................
The adult.......................................................
Resting position ---..---------.....-........................---......
Note of female ---. ......-.- ....... .... ..------- ------------
The eggs-..----------.... -.. -..............--....--- .--- ..---.--.
The larva-----------------------------...------------------...--
The pupa ------ ----------- --- -- -- ------------------
Natural breeding places of Anopheles.-----------------------------
Other species of Anopheles -------------------------------------
Distribution of the species of Anopheles in the United States ............
The genus Psorophora ----..-...- ........ ..- ....... ..- ...... ............
The genus Megarhinus ------------..................------------.--....-......--.............
The genus Aedes -.....--------------------------....------------.....
The natural enemies of mosquitoes ----..--..---------.--------------.....
Remedies against mosquitoes...-------......................................
Remedies in houses and prevention of bites --------------------
Remedies for bites........-- ...-- ....--------... --..--.......................
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..-.---- .. ....- ...--- .. 13
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Destruction of larva- andi abolition of breeding plaes .................

Drai a ............................................... .. .....,
Practical use of fish-.......----------..... ..........a....:. a
Artificial agitation of the water ........................... :
T.ater ume of kerowne ...' i
Other larvicides ...... -....... -... .... ...... ....... ...... ..... .......
Permanganate of ioth ............w- -....................i -
IPnOreprietary iiiitxit 'N --...-........-....................
Exiriiiient (If ( li iiaw C( agrandi a......... .. ......e.
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Tar and itn Itt'iiixinn ls................. ....................
EU lyjtU r ................ .......... ......... ... ... ....... ...
Drainage anmi .ni.ninity' work-.......... ............ ..........
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ILLUSTRATIONS.
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Fit. 1. Culex pungens: Eggs and young larve .......---..........---............ .'*ii .. ..i r.
2. ('ulex pungent: Heal and mouth" parts of larva---------------.- iF
3. Culex pungens: Full-grown larva and pupa.... ................. ----
4. Culex pungens: Adults, male and female, with structural details..- ::
5. Culex t.enioftivnichus: Female -------... --... -----------................, :
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Ano heles quad ri n iau latu: Adult male and female-------..--------- :i
7. Resting positions of Culex and Anopheles compared---................ :;
8. Resting positions of Anopheles on vertical and horizontal walls----
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9. Resting positions of Anopheles and Culex, after Waterhouse. -----. .f.1 ....
10. Anophleles quadriniaculatus: Egg mass...-....-...-----------.....-.,-.. Si
11. Anopheles quadrinmaculatus: Isolated eggs from above and belowa..` S :
12. Anopheles quadritnaculatus: Newly hatched larvEe- --. 36%
13. 1Half-grown larvae of Anopheles quadrimaculatus contrasted with maw
stage of Culex pungent --------------------------.......................................... 37..,.
14. Feeding position of larva of Anopheles quadrimaculatus oontrmusd
with that of Culex pungens ------------ ------------- .-.-- ---
15. Anopheles qualriiaculatus: Full-grown larva, showing head Er m ::
above and below.------------- -----------------------------...39
16. Anopheles quariniaculatus: Pupa contrasted with that of Culex -
pungens ....................................................-------------------------.
17. Anopheles punrtiienniI: Head of full-grown larva from above ....... 41::::
is. Anupheles punitipenniis: Adult female.--------------------------- 43 '
19. Anopheles crucians: Adult female............................. 4: 4
20. Psorophora ciliata: Adult female-.--........--...-..-..-.....---.- :5
21. Megarhinusrutilus:4 Adultfeale--------..------- .- 4i: i
22. Aedes sapphirinus: Adult female--n...................................


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NOTES ON THE MOSQUITOES OF THE UNITED
STATES.


ON MOSQUITOES IN GENERAL.
Abundance of mosquitoes.-The literature of popular entomology is
full of instances of the enormous numbers in which mosquitoes occa-
sionally occur. Persons interested in this line of curious reading
should consult Kirby and Spence's An Introduction to Entomology,
Volume 1, pages 112-120, and Frank Cowan's Curious Facts in the
History of Insects, pages 278-286. Referring to their occurrence in
the far northern regions, Kirby and Spence, for example, say: "In Lap-
land their numbers are so prodigious as to be compared to a flight of
snow when the flakes fall thickest or to the dust of the earth. The
natives can not take a mouthful of food or lie down to sleep in their
cabins unless they be fumigated almost to suffocation. In the air you
can not draw your breath without having your mouth and nostrils
filled with them, and unguents of tar, fish grease, or cream, or nets
steeped in fetid birch oil are scarcely sufficient to protect even the case-
hardened cuticle of the Laplander from their bite." Elsewhere the
same authorities say: "In the neighborhood of the Crimea the Russian
soldiers are obliged to sleep in sacks to defend themselves from the
mosquitoes, and even this is not a sufficient security, for several of
them die in consequence of mortification produced by the bites of these
furious bloodsuckers." Elsewhere: "And Captain Stedman, in Amer-
ica, as a proof of the dreadful state to which he and his soldiers were
reduced by them, mentions that they were forced to sleep with their
heads thrust into holes made in the earth with their bayonets and
their necks wrapped round with their hammocks." Humboldt says:
"'Between the little harbor of Higuerote and the mouth of the Rio
Unare the wretched inhabitants are accustomed to stretch themselves
on the ground and pass the nights buried in the sand 3 or 4 inches
deep, leaving out the head only, which they cover with a handker-
chief." Theodoretus says that Sapor, King of Persia, was compelled
to raise the siege of Nisibis by a plague of gnats, which attacked his
elephants and beasts of burden and so caused the rout of his army.
In modern times nearly every hunter and fisherman in this country
has had experience with mosquitoes which renders easy of belief all
of the old-time stories. The instance mentioned in Bulletin No. 4, of
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the observations by Mr. Schwarz, of this office, at Corpus
Tex., could be practically duplicated by many persons. H
that when the wind blows from any other direction thansouth
dreds of thousands of millions" of mosquitoes blow in upon them
Great herds of hundreds of horses run before the mosquitoes an '
to get to the water. With a change of wind, however, them
blow away. Many regions, especially along the seacoast v
actually rendered uninhabitable by the abundance of mosquitoesm 4%%i
they have lbeen a serious drawback to the settlement of many oi
wise advantageous and fertile localities.
Dr. Otto Lugger reports, on pages 216,217 of his annual rep .
1896 as entomologist to the Minnesota State Agricultural ER In r
Station an interesting series of observations to determine the numb
of mosquitoes which may be bred in an ordinary rain barrel. ..
observations were made at St. Anthony Park, Minnesota. On July: m,:mm..m......
1896, the water in one barrel was filtered and was found to conoi!:Sm1::;: i.:
17,259 eggs, larvae, and pupae. On July 22, 1896, by a similar proc :-
ess, 19,110 mosquitoes were counted. When we consider that Hl
least twelve generations may breed in a summer it is obvious, fro int
Dr. Lugger's account, that a neighborhood may be well supplied
from one neglected rain-water barrel.
Alaskan and other far northern mnosquitoes.-Since the opening p m:'
of the gold fields in Alaska and the great influx of miners and trader'. :
knowledge of the abundance and ferocity of the Alaskan mosquitoes
has become widespread, and surveying parties from the United Stats i
Coast and Geodetic Survey and the United States Geological Survey
in starting for Alaska for their summer's work are in the habit of am m..
suiting this office for the best remedies for mosquito bites. Those
who were in Alaska the preceding year always state that they never '
experienced or even imagined anything in the mosquito line quite eqmual:
to those found in our northern territory. Mr. W. C. Henderson, O. :
Philadelphia, who spent some time in Alaska recently, writes: "They.m:m::::::.
existed in countless millions, driving us to the verge of suicide o& r
insanity." Nothing has as yet been published regarding the exact
species found in Alaska, but Mr. Coquillett has determined 6dmmme mmmmm.m.
xobrinun and Cul-.r hqd i If er from specimens collected by Prof. Trevor
Kincaid on the Harriman expedition of 1899. 0. wmsobrinua wa m
collected at Sitka June 16. and Yakutat June 21; and 0. impWyger ws
taken at Sitka June 16, Yakutat June 21, Virgins Bay June 26, Wd..
Popoff Island July 8-16. '
That the knowledge of the existence of mosquitoes in boreal regionsi::::
is not new is shown by the quotation just made from Kirby and Spenaii:,
and in Bulletin No. 4 the writer mentioned some of the instances iofi .I7ji
record by arctic explorers, citing, for example, the narrative of C.-'" Fr
Hall's second arctic expedition, in which the statement is made t hat 1

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mosquitoes appeared on the 7th of July, 1869, in extraordinary
abundance, and of Dr. E. Sterling, of Cleveland, Ohio, who sent us an
account of the appearance of mosquitoes by thousands in March, 1844,
when he was on a snowshoe trip from Mackinaw to Sault Ste. Marie.
STheir extraordinary appearance at that season of the year was remark-
Sable as indicating a most plentiful hibernation. Mr. H. Stewart, of
SNorth Carolina, was also quoted as noticing, on the north shore of
Lake Superior, in 1866, in the warm days of March, when the snow was
several feet deep and the ice on the lake 5 feet in thickness, that mos-
quitoes appeared in swarms, literally blackening the banks of snow
in the sheltered places." Dr. Otto Lugger was also quoted as stating
that Cider cotsobrinu. made its appearance in April, 1896, at St.
Anthony Park, Minnesota, in a genuine swarm with a heavy snow-
storm, at a time when all the lakes were covered with ice.
Dr. Lugger has also called the writer's attention to the fact that Dr.
SEmile Bessels, of the Polaris expedition, was obliged to interrupt his
work in Davis Straits (latitude 72 N.) on account of the multitude of
these insects.
Length of life of the adult mnosquito.-A curious and as yet unex-
plained point in regard to a phase of mosquito existence is their extra-
ordinary abundance at certain times upon dry prairies miles from water,
which has led to the very generally accepted idea among far Western-
Sers that all mosquitoes do not need pools of stagnant'water in which to
breed, but that certain of them must have some other breeding habit.
This supposition still appears incredible to the writer, who is much
more inclined to attribute this abundance in dry regions to a greater
longevity on the part of the adult mosquitoes of certain species than
has been proven, thus enabling these great swarms to live from one
rainy spell to another, no matter how widely separated. The gravid
.females of most insects seem to be able to live until they have oppor-
tunity for appropriate oviposition. The writer is frequently asked as
to the duration of the adult stage of mosquitoes, but beyond the
statement that although adults hibernate, living in this condition from
November until April or May in the latitude of Washington, he is
obliged to state that they die rather quickly in confinement in the
summer. He has had living specimens of Anopheles quadrimaculatus
confined in breeding jars for eight days, all dying, however, at the
expiration of that time. Dr. Woldert has kept adults for fifteen days
in a wide-mouthed bottle in which was placed a small slice of banana,
the gauze with which the bottle was covered being sprinkled every
day. Other specimens were kept from fifty to sixty days, but this
was in the late fall, and many of them would probably have hiber-
nated. Dr. Manson states that they may be kept for weeks in a glass
vessel containing a piece of ripe banana, the banana being renewed
every three or four days.





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Lft ,etfr!i/,f n,,tqufitoes in yeneml.-In general terms the
of ti, ('lCdiii'ht....li family to which the true mosquitoes..9
may briefly IN summed up. All general statements heretofore.
vbeen based upon the life history of one or two species oft .i.
(Cul, Xvyet it is ,certain that such remarks will not only not
the whole fanlily, but that, except in a general way, they will no
for all tihe p eis of (Culex. So far as is definitely known, theblW*
of all ilIosMIlitoe's :tir' aquatic, although they are true air brelm viq + ^ +
thliat is to say, they ,must. come to the surface of the water to br-atibib.
Thv' arI rapid lrh'o'h'rs. andl pass the pupal condition also in Wb *
lint tloiati lg 11H tra ti:y alt th surface. They pass through several ....i....
erntionIs in tlhe ol.its' if a year and hibernate as. adults. Hiberating
mOS(Iiitoes inmy fre'iu-Itly be found during the winter months iha:W
lbMa1'u ) and( in thl e 'lirs 21(and cold garrets of houses. Dr. W. S:::
ThaYer. of laltimnre, infornis thw writer that he found AnwphAJ
'erf,,',.; :a6d t. ij ,/,1';maeul ftti, hibernating in enonnrmous numbers Is
4arns ar New (O)rleanTis. cluiste'ringr under the roofs and on the walk .:
In thl. ext ivrein Southilrn Statis d many viosquitoes are active all through
tli' wiviiter, and nmosluiito inrs are almost as necessary at Christm :as 9
tine :as (lurig tiI. sulminmer. [
]J'1010 ft',d/ iu,, ,jmni;tev..-It is a well-known fact that the adult i
n1ah1 l ios.luito( d4)'s Dnot necessarily take nourishment and that the |
adult female doe. s not necessarily rely on the blood of warm-blooded
animals. F'li mouth parts of the male are so different from those of
the femiale that it. is probable that if it feeds at atll it obtains ib .
food in :Li quite different manner from the female. They are often
observe'e'd ipling; at drol).ps of water, and( in one instance a fondnem
for molassesl l lihis 1'men rec.orded........
T'en writer has already placed on record the instance in which him
colleaue, M lr. E. A. Shwarz, observed a male mosquito sipping beer,
but thie itlost iintenrstiiig instance of alcoholism of the male mosquito .
whicli has coims to his notice was (described in a letter retveived lt
spring froin l)Dr. St. George Gray. of Castries, St. Lucia, British
\Vest Indies. l)r. (Grav wrote:
"TIit iiialUa, esif'Siallv i '. ,piviim, are very fonid ci'f wine, and almost every day I.
can catnli cmnte *,r t "i---alwas iiiales--in the neck of the tde'aniter or in a wineghi
that has jiut ,r.ii .-i,. 1'1bit a few iii isqitoes under a Ib?1 jar oneday in order to
watch tltii. I put a inllgl ,irop tf port wine under the jar, ag I had herdf that
iiii,.iSnittipe ctill IN. kelit alive' fr a i mg time on wine. When I went to lookat
themi a fIw l m's latter I fimnid them all apparently lead, so I put them in a d.ry
Little, intenlingI t,- piin tlhimt later. When I went to pin them shortly aftervwaki
they were all r tag-triiig alxit in tie iiiost ridiculous mianner-they were drnnk!**
The female iniosquitoes are normally without much doubt plat
feede.rs. Vhy t.hey should draw blood at all is a question which W i'!
not bee'n solved. It has been surmised that a supply of highly nugr '.
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tire fluid is necessary for the formation of the eggs, but this supposi-
tion is at once emphatically negatived by the fact that mosquitoes
abound in regions into which warm-blooded animals never penetrate.
The statement which the writer has elsewhere made, that not one in a
million ever gets the opportunity to taste the blood of a warm-blooded
animal, is unquestionably an underestimate. There are in this country
enormous tracts of marshy land into which warm-blooded animals
never find their way and in which mosquitoes are breeding in count-
less numbers, and when we get within the Arctic Circle and other
uninhabited regions the point is emphasized. Scattered through the
seven volumes of Insect Life are records of the observation of the
vegetarian habit, one writer stating that he has seen mosquitoes with
their beaks inserted in boiled potatoes and another that he has seen
watermelon rinds with many mosquitoes settled upon them busily
engaged in sucking the juice. That they may and occasionally do
feed upon other than warm-blooded animals, however, is evidenced
by an observation by the late Dr. H. A. Hagen. who mentions taking
a species of mosquito in the Northwest which was engaged in feeding
i upon the chrysalis of a butterfly, while there are several instances on
record where they have been observed puncturing the heads of young
Fish and killing them.
1 How far will mosquitoes fly?-The question is often asked: '"H ow
Sfar will mosquitoes fly from their breeding places, or how far can they
Sbe driven by the wind" In some instances this becomes a matter of
Practical importance, since, if mosquitoes fly great, distances, extermi-
Snative work on the breeding places near a house or community will be
of comparatively slight avail. There exists on this point a difference
K of opinion. In a discussion at the meeting of the As.sociation of Eco-
nomic Entomologists at Boston, in August, 1898, Dr. John B. Smith
stated, in referring to the possibility of mosquitoes being carried by
strong winds to-considerable distances, that he had noticed that they
would not rise or take flight when a brisk breeze was blowing, and
that 'even a comparatively slight breeze will keepl) them from upper
stories in houses. He, therefore, doubted the wide distribution of
mosquitoes by high winds. Dr. H. T. Eernald stated that at Cold
Spring Harbor, Long Island, with a north breeze there are no mos-
quitoes. With a south breeze, on the other hand, they are often very
Troublesome, especially after a prolonged gentle wind of five or more
hours' duration. There are no pools in the center of the island, and
Sthe mosquitoes are supposed to have been carried from the south shore,
a distance of some 15 miles. This question became a very practical
Sone to the members of the Richmond County Country Club on Staten
SIsland, in their operations against the breeding places of mosquitoes
Son the island, since, if a new supply could be carried over by the
i winds from the New Jersey coast near by, a large portion of their




............






141
.... .::: .* EE .....
1 4 .......: 7?/ii..

labor would be wasted. Mr. W. C. Kerr, the originator of tho
quite work at that place, and. an excellent observer, is. ,ded yt .
the opinion that mosquitoes are not brought over from New:JoraiJ'
Almost everyone must have noticed the habit of mosque se4ii4:i.. 4...,
clinging to branches of trees and grasses during a high wind, .....
ing out in flight as the wind subsides, but there must be i S (
when they are greatly aided in spreading by such gentle wi
those mnientioned above by Dr. Fernald.
In this connection an observation made by Mr. B. M. MBesi.i::mIii
Baltimore is significant. He found that by treating the privy vwatl:il::t
in his backyard with kerosene, the supply of mosquitoes to the koui!'11^
was greatly reduced, although there were many other breeding places
only a little farther removed. '
Another significant instance was mentioned by Prof. Herbet
Osborn at the Boston meeting of the Association of Economic Emk .:
mologists. He said that in dry seasons the small pools within a qua.
ter to a half a mile from the college buildings at Ames, Iowa, dry up.
and the mosquitoes disappear, in spite of the fact that within about a
mile there are large pools which never become dry.
On this point Mrs. C. B. Aaron writes very sensibly as follows
(Dragon Flies n,. Mosquitoes-The Lamborn Essays, Appleton & Co,
1890, pp. 35-36):
The migration of mosquitoes has been the source of much misapprehension on tle
part of the public. The idea prevalent at our seaside resorts that a land breesebridp
the swarms of mosquitoes from far inland is based on the supposition that it iscapbb
of long-sustained flight and a certain amount of battling against the wind. Thi isia:
error. Mosquitoes are frail of wing; alight puff of breath will illustrate this byhurbil
the helpless creature away, and it will not venture on the wing again for some tinme fte .
finding a safe harbor. The prevalence of mosquitoes during a land breee ks easily
explained. It is usually only during the lulls in the wind atsuch timesthat Qnisxa
fly. Generally on our coast a sea breeze means a stiff breeze, and during theseevem tim
Odonata, and often the robust and venturesome Tabanidse, will be found hovering on
the leeward side of the houses, sand dunes, and thick foliage. In the meadow aouth
of Atlantic City, N. J., large swarms of Culex are sheltered in the denpe gram or
wind-battered tree tops on the off side of the sand dunes. Here, in common with li
localities so exposed to searching wind, the trees and large bushes are much sbMted
in growth and battered down to j flat top and common level by the wind. In ths
matted branches, dense with the close-clustered foliage, the mosquitoes may be dis-
covered in such numbers as to bring despair to the heart of the student who is plot-
ting their final extermination. While the strong breezes last Culex will stick clae
to these friendly shelters, though a cluster of houses may he but a few rods off, iled
with unsuspecting mortals who imagine their tormentors are far inland over the lit
meadows. But if the wind dies down, as it usually does when veering, out oeM
swarms upon swarms of the females intent upon satisfying their depraved tat o
blood. This explains why they appear on the field of action almost immediately..
after the cessation in the strong breeze; on the supposition that they were blown b:.r,:
inland, this sudden reappearance would be unaccountable. ": :i
Carriage of mno8quitoes mby railway train.-The State of New Jehr .::::ey::::
has an unfortunate reputation in connection with mosquitoes. WhIl
& A :::* "*......:: :
":* *^.::...:







15


Sit is undoubtedly true that mosquitoes are very abundant in most parts
Sof the State, that fact does not mean to the writer that in the greater
Part of the State there are any more breeding spaces or that mosqui-
Stoes are any more prolific within the State borders than elsewhere.
SIt does, however, seem to him that there is constant carriage inland
from the marshy seacoast of very many mosquitoes, but by this he
does not intend to convey the idea that they are carried by wind or
that they fly to any great distance inland. There are other means of
conveyance, and of these railway trains seem to be very important.
All through the summer evenings many trains are started inland from
Weehawken, Hoboken, Jersey City, South Amboy, Long Branch,
Atlantic City, Ocean City, and Cape May, N. J. Many of the cars, as
the writer knows from experience, contain mosquitoes by the hun-
dreds. In this way unlimited quantities of mosquitoes are carried
Unlimited distances, and, emerging from the cars, will start to breed
Seven in localities where mosquitoes are ordinarily rare, or would be
Srare under ordinary conditions. In this way even mountain resorts
Swill get their supply of lowland mosquitoes, and with the improve-
I ment of railway service and the increase in number of through cars
the danger is constantly increasing. The writer knows of one instance
in the Catskill Mountains in New York where the infestation of a pre-
viously uninfested place could have been brought about in no other
way. Through parlor and through baggage cars now run from Jersey
City and Weehawken into the heart of the Catskills and through trains
from Boston into the White Mountains.
In the same way through cars run from Baltimore into the Blue
Ridge, and thus a constant source of supply may be, and undoubtedly
is, kept up.
How long can the lavce live out of water?---At the meeting of the
Association of Economic Entomologists above referred to, Dr. Smith
asked if it were possible for mosquitoes to breed in mud, and sug-
gested that there was no reason to believe that the actual presence of
Water was necessary for all mosquito species. The writer has seen a
statement from some Californian, which he is unable to place at the
present time, to the effect that there is a prevalent belief in some parts
of the United States that when a surface pool dries up half-grown
larvae may exist in the drying mud for some time, reviving with a
Fresh rain. Mr. C. A. Sperry, of Chicago, wrote us early in 1899
and advanced the same theory. He said that experiments made in
small vessels had always been very unsatisfactory to him, and that he
abandoned that method and sought the natural breeding places for
Investigation and experiment.. Early in July he found a wet-weather
pond with mosquito larvae in it, the pond being nearly dry. In a few
days the water was all gone. He examined closely and discovered no
dead larva. In about a week it rained, and as soon as the rain
4


.. .:: r ..:. .... ,,, ::E .. .





stopped he went to the place and found tbhe mosquito larvean:l:::
the water as lively as ever, and they began to issue as adut:
week from that time. Again he discovered a place whre thi
had nearly dried lup, and hundreds of mosquito larvae WnM'"
hint (.I the wet ground. Three days later it rained, and- he
larva- in the water as lively as ever. In the same way Mr.
S. Pa.-.hsall. of Ntwtieid, N. J., has communicated to us o
of his owi whilh indicate to him a possibility thatosqu
breed in grss o r ni moist earth. ......i.:
Experiments made 'at this office on a small scale in isi
have shown that the larvae of Culex will exist for some litMtle .h. i
wet imild. and some o(f them will successfully transform
hais heen, added. In no case, however, were we able to revive: -he'jfUu
in inuil from which the' water had been drawn off for more thIan 'f i
(igit Iulirs,. and after twenty-four hours only a small propor.taia :i:
thl larva' revived. An interesting pool has been under obsetravit.r: ,
drij ng thi. prese nt month. The pool contained a surface area of abcSfi't ..
24 SijUIare feet. and was fed entirely by rain water and surfacedmim ..i
age. preaching a depth when futill of about 1 foot. All through the ..... ..i
mn.r tiis po ol is well stocked with mosquito larvae. After a &o -eliat
long drought the water was observed on July 18 to have evapoit:;il
almost ,itirely, a small puddle in the center of the cavity, conlainl .:i,;. .
only 3 or 4 cubic inches of water, remaining. It was dark in cerg;*..|
owing to the drainage from a manure pile near by, and to the :sem Si
. ". . ":..... :.
observer showed no signs of life. The water in this little puddle w i
very shallow. (On dipping in a coffee strainer, however, it was foiad.. ...
......... L. :!. '
to 1C literally massed with nearly full-grown mosquito larvae, Iaity-
hundreds of which had been brought together into this restrlpt.Y -
pllace. The drying continued until there was almost no water.I .i'
~ ~ ~... i ... .. ?" ..L .!
()On tihe eight of the 20th cane a heavy rain, followed with si- t a ..:
heavier one oni the morning of the 22d. On the 23d the poolws. L
foniid to be entirely full of water and to contain its usual stat-:t:.::::'
miiosqiito larv, a'vw. i:-
T'his mav be safely said to indicate the usual habit of mosquito
larva in e(vaporating pools. As the water gradually recedes to wrEid ';
the deepest portion of the excavation, the larvae recede with it. o0M,..- .i.
cent'ratiiig themselves at the deepest point, i. e., at the point wbe".:i
the moisture remains longest. Knowing as we do, then, that ev e.:....
in tihe absence of ainy free water the larvae will remain alive in ma :" A
nmud for from twenty-four to forty-eight hours, it is evident tel^ ^^
A
such a pool as the one described gradually drying would give t= ..=:==M
atpparaitnci' of having been practically .dried up for some daylise1fiM...i....i,.
the last, cubic inch of free water has entirely disappeared. Tb .. .
,ent rattion of lmany larvaw at this point in the manner which has-lI '".:ii
described could not fail to give rise to the belief that mosquito WOiWmn*


...........






17


will exist in the absence of free water for a much longer period than
is really the case. In the opinion of the writer, where the mud dries
up entirely the mosquito larva3 are necessarily killed, but that they
may exist in very wet mud for a longer or shorter time is true.
An interesting observation bearing upon this point has been made
by Dr. St. George Gray, of Castries, St. Lucia, British West Indies,
and reported in the Journal of Tropical Medicine, London, May 15,
1900. He says that on February 7, 1900, he examined a spot where he
had obtained larval of Anopheles a few months before. The pool had
been dry for three weeks, hardly any rain having fallen during that
time. The surface of the mud at the bottom was cracked and dry,
although soft enough under the crust. He put the mud into a clean
pickle bottle and put about 3 inches of filtered water over it, but there
was no result. He also took some grass from the sides of the pool and
put that grass into another pickle bottle, adding 3 inches of filtered
water. On the following morning he found a few minute larvae
wriggling about in this bottle. These rapidly grew in size, and he
soon had a half dozen healthy looking larvar in his bottle. On the 21st,
a fortnight after he had taken the grass from the sides of the pool, he
reared the imago of Culex teniatus. From this observation he argues
that some species of Culex, at any rate, do not always lay their eggs
on the surface of the water, but where they will be washed into the
pool by the first heavy rain. Other similar experiments were failures.
This record is a very interesting one, but, like all isolated observations,
needs verification.' It may here be mentioned that Drs. J. W. W.
Stephens and S. R. Christophers, in their article on "The distribution
of Anopheles in Sierra Leone," published in the reports of the malarial
committee to the Royal Society (London, July 6, 1900), stated that
they were unable to hatch the eggs of Anopheles after desiccation on
blotting paper for more than forty-eight hours, although they hatched
after twenty-four and forty-eight hours' drying, respectively.
The number of species of mosqtuitoes.-As regards the different kinds
of mosquitoes, about 250 species are known, of which only about 30
have been found in the United States. These are divided into 5 differ-
ent genera, each of which will receive consideration in the following
pages. Of the malarial genus Anopheles, Mr. F. V. Theobald writes
us there are 27 species in the British Museum collection.

MOSQUITOES AND MALARIA.
This is not the place to discuss at length the history of the discover-
ies which have brought about the very perfect proof that mosquitoes
may and do transfer the malaria germ from a malaria patient and
L'Dr. Walter Reed, U. S. A., tells me that Dr. Lazear has just made a similar
observation in Cuba.
iL 3949--2




. .. .... . i
.. .. .. ....


18 H

deposit it in the blood of a healthy person. Those in
referred to the admirable paper entitled "On the r6le of .
Arachnids and Myriapods, as carriers in the spread of ItshI
parasitic diseases of man and animals; a critical amnd historical
by George IL. Nuttall, M. D., Ph. D., published in Volume 4r
the Johns Hopkins Hospital Reports, and to later American so
among which may be mentioned that by Dr. W. N. rkey iI
New York Medical Record for December 23, 1899, by Dr. "Aft
Woldert in the Journal of the American Medical Associatien forIW,1
rtary 10, 1M,),') and 1by Dr. William Britt Burns in the Memphi. Mal..- .i .
cal Monthly for March, 1900. One of the most thorough of the..st<..
reviews will be found in Nature for March 29, 1900, pages 59,
entitled "N Malaria and mosquitoes," a lecture delivered at the R :p::it::i.^
Institution of Great Britain on March 2, by Maj. Ronald Ross, D. P. H,W I
M. R. C. S., lecturer in tropical medicine, University College, Liveri-^"
pool, himself one of the workers whose results contributed mao'ty::
materially to the establishment of definite proof. Another t'
account will be found in the Popular Science Monthly for July, 1S :O j
by Dr. Patrick Manson, entitled "Malaria and the malarial parasite. 'T::::.
It should be stated here, however, that only the mosquitoes of t he
genus Anopheles have been found to contain the human blood par-
sites, although it does not appear from the published accounts which" i
have met the writer's eye that any other genera than Anophelee ad,
Culex have been studied in this connection.
The Italian observers have found that all three species of the human
Hamnanioebidfe are cultivable in Anophelexs danger and not only in '
this but in other Italian species of Anopheles, while they, together:
with Ross and other observers, have failed to cultivate the pariitses
in Culex. The same fact is upheld by the extended observations made
in West Africa and in this country so far as observations have been
made as yet. The writer, however, wishes to emphasize the point .I
which he made before the American Medical Association on June 6,
1900, that American physicians, especially those in the Southern Stae, :
should not delay the investigation of the very large mosquitoes of the.Y
genius Psorophora and Megarhinus Ltom the malarial standpoint. Bot .h.:
of these genera have been figured and described in succeeding psg. :
:: "liE: :" *:;
SYNOPTIC TABLES OF THE NORTH AMERICAN MOSQUITOES.
In order to enable the ready determination of our different meiM-::::".:.......
quitoes the writer published in Circular 40, second series, of thisoffie 1
in February of the present year, a series of tables, drawn up a. .:......
request by. Mr. D. W. Coquillett, of the office force, comprising (1)i
'Dr. Wldert's article contains a good account of the internal anatomy .of :...w........
toes and describes his methods of dissection. .... ....... ...." .







19

synopsis of the five genera under which the long-beaked, blood-suck-
ing species known to occur in North America were divided; (2) -
synoptic consideration of the species of the genus Culex, divided into
(a) table of the recognized species, specimens of which occur in the
National Museum collection, and (4) an account of the unrecognized
species, which are known only fromni the literature; (3) a synoptic cm-
sideration of the species of the genus Anopheles, divided into (a)
recognized forms, and (b) unrecognized forms; (4) a brief description
of the only valid known species of the genuis Psorophora; (5) a synop-
tic table of the three known species of the genus Megarhinus; and ((6)
a synoptic consideration of the two known species of the genus Aedes.
Mr. Coquillett's tables are here reprinted with slight changes:

I.-GENERIC SYNOPSIS.

The following table contains all the genera of the long-beaked mosquitoes known
to occur in North America. The males are readily recognized by the antennae being
densely covered with long hairs; in the females the hairs of the antenname are short
and very sparse:
1. Palpi in the male at least nearly as long as the proboscis; in the female less than
one-half as long. ----------------------: -----....-----..-..........------..---.----. 2.
Palpi in both sexes at least almost as long as the proboscis----------........... lnopbcl,,s.
Palpi in both sexes less than one half as long as the proboscis-.....-.-..- lAedes.
2. Proboscis straight or nearly so, colors of body brown and yellowish---------.......... 3.
Proboscis strongly curving downward toward the tip, colors bluish or greenish.
Megarbinus.
3. Legs bearing many nearly erect scales--------...-----......-----....------- Psoruphor..
Legs destitute of such scales----..-------....------------------..---------.... Culex.

II.-(ENrts ('ULEX.

(a) RECOGNIZED SPECIES.


1. Front tarsal claws bearing a distinct tooth near the mi(ldle of the underside of
each.............................................................--------------------------------------------------------.... 3.
Front tarsal claws bearing two teeth on the underside of one claw, and one on
underside of the other, proboscis destitute of a whitish hand near the mid-
dle ............................................................... ----------------------------------------------------------.... 2.
Front tarsal claws with one tooth on underside of one of the claws, none on the
other, bases of tarsal joints white, proboscis destitute of a whitish band near
the middle ..----.-------.-----..........---..--------.----...---------. fsrian.s Fabr.
2. Tarsi distinctly white at bases of the joints------------------ r.rrifa)nRN Walk.
Tarsi not white at bases of the joints ---------------------consobrinus Desv.
3. Proboscis destitute of a whitish ring near the middle ---------......----..------- 4.
Proboscis with such a ring, ends of tarsal joints white----------- tarsalis Coq.
4. Bases of tarsal joints not white--...--.-----....-----------...----------.....--------....... 5.
Bases of tarsal joints white-----------.........-------....-----....-------. stimulans Walk.
5. Petiole of submarginal cell less than one-third of the length of that cell.
pungens Wied.
SPetiole of submarginal cell at least one-half of the length of that cell.
impiger Walk.
Females.
- 1. Front tarsal claws bearing a distinct tooth near middle of underside of each.- 2.
Front tarsal claws destitute of teeth ..............-------------------.-................... 7.


L." .
N...; :
^l,,', :!Kii" ':


Pill- ", 11 lu







20
:,':iii ~ Miii!!


2. Probocis destitute of a white ring near the middle ... .................,
Proboscis marked with such a ring, bses of tarsal joints white.
........ l: :l***1 i !!! i J
3. Bases of tarsal joints distinctly white.....................:...-... '
Bawes of tarsal joints never white .......................-... -.-.. ...
4. Mesonotuiin marked with four stripes of silvery scales........... fa cust
Mesonotuan destitute of such stripes: :
Fifth joint of hind tarsi white ............... -..-......- '
Fifth joint, except its extreme base, dark brown ....... ... Afmwl WSlW
5. lest two jointsof hi n'! tarsi never white........----...................:,
lAmt two joints of hind tarsi snow white......................-. pot W ...
6. Abdomen marked with a cross band of whitish scales at base of each segment,.J
Abdomlnen never marked in thin manner, but with a cluster of whitishflad at, :
front angles of sonime of the segments-......................... tia-ea-tS : Iu b
7. Proboscis marked with a distinct whitish ring near the middle, tarsi white at ; '
sutures if the joints-...............................................-... -. -:
Prolb iscis destitute of a whitish ring near the middle ----..-....--.-....... 9. :, i
S. Tarsal joints white at bases only ............................perftrbus Walk.' :. !
Tarsal joints white at lxboth ends-----------.................---.-----------.......tara Ooq.
t. Tarsi white at bases (of joints..--.....--....-......---.......-.................. 10.
Tarsi never white at lbass of the joints ---------...........---.----------------......... 1.
1(0. Meaonotumin never marked with stripes of silvery scales..---.................. 1.
Mesonotuin marked with four stripes of silvery scales, first tarsal joint never
marked with a whitish ring near the middle---------------- ................... sigmfer Ooq.
11. First tarsal joint marked with a whitish ring near middle of each.
excrucan Walk.
First tarsal joint destitute of such a ring-- ..-----------.......-------....- ezcitm Walk.
12. Petiole of submarginal cell less than one-third of the length of that celL
n VigemwW .d.
Petiole of submarginal cell at least almost one-half of the length of thatell.
conwbrinu Deo.
(b) UNR(ECOG;NIZED MPECIEI.

annulnits Schrank. This European species was credited to our fauna by men
Sacken. The description agrees fairly well with specimens which I have identified
as r.rcitos, Walker, except that in the latter there is no white ring on the lemor
toward their apices.
boRcii Desv. Probably a nirubbed specimen of pungen..
nigripcn Zett. Black, the legs of the male dark yellow, hairs of pleura of female .......
gray, a band of white scales at base of each segment of her abdomen. ".
rubidins Desv. lhe description was apparently founded on a rubbed specimen of
P1oropdora ciliata.
tIslceus v. d. Wnlp. Is probably a somewhat injured example of conWbrkwu.
iucidens Thomson. Is evidently a synonym of impiger Walker.
,iguii Bellardi. According to the figure and description, the bands of black scales
are at the haes of the abdominal segments; in the recognized species these bands are
always at the apices of the segments. In other respects this species must greatly
reseinmble pungrs.
r-hrnsi. Bigot. Apparently founded on a badly nirubbed specimen of pungemns.
frater DI)es. This name was proposed for the Cide.r fasciatut of Wiedemann, under
thile impression that this is not the same species as the one described by Fabriciun
under the same name. It seems quite certain, however, that the word. "proboseta"
in Fabricins' description was simply alapsus for palpii," and with this emendatio,
the two descriptions agree very well.
nme.irevrna Bellardi. Is evidently a synonym of posticatus. ,
prefMonnl Walker. Is probably a synonym of stimulans. In some specimens of
tins specick the light color at the bases of the tarsal joints is very indistinct.
territaui Walker. Is apparently a synonym of pungents.

'Mr. F. V. Theobald, after studying Walker's type of perturbas, writes us that It
hlias toothed claws in the female. '




. .:........ ...

H ji, t
...- i ijii :,







21

S Our recognized species of Culex and their synonviyms may be listed as follows, the
I synonyms indented:


consobrinus Desv.
? annulimanus v. d. Wulp (Ano-
pheles).
impatiens Walker.
inormatus Williston.
pingu8is Walker.
inctor Kirby.
testaceus v. d. Wulp.
excitans Walker.
? annulatus Osten Sacken (nev
"Meigen, etc.).
excrucians Walker.
fasciatus Fabr.
frater Desv.
mosquito Desv.
taeniatus Wied.
impiqer Walker.
smplacabilis Walker.
incident Thomson.
? quinquefasciatus Say.


pertiirhans Walker.
posticatum Wied.
? mezicanw Bellardi.
IniITnicus Say.
plinqensA Wied.
? boseii Desv.
Y eubensis Bigot.
? It.rilans Walker.
igqnifer Coquillett.
stim ulins Walker.
? provocans Walker.
taiueu iorhynchIus Wi ed.
dmnmosu8 Say.
sollicitans Walker.
tarsnlis Coquillett.
triseriatus Say.


III.-GENUS ANOPHELES.

(a) RECOGNIZED SPECIES.


1. With a yellowish white spot near three-fourths of the length of the front margin
of the wing; scales of last vein white, those at each end black- punctipennis Say.
Without such a spot---------------------------------------------...................................................... 2.
2. Scales of last vein wholly black, palpi wholly black....... quadrinuiculatus Say.
Scales of last vein white, marked with three black spots, palpi marked with white
at bases of last four joints..................-.................. crucians Wied.

(b) UNRECOGNIZED SPECIES.

The following species which have been credited to our country have not been
Recognized with certainty; some of them probably do not belong to the present
genus, while a few were evidently founded on badly rubbed specimens in which the
distinctive characters were therefore wanting:
annulimnanus v. d. Wulp. I strongly suspect that this does not belong to the present
genus; the description applies fairly well to the male of (dex consobrinus Desv.
ferruginosus Wied. This author proposes this name for the species previously
described by Say under the name of ('ule.x quinquefasciatus, but the description which
he gives differs so decidedly from the one published by Say as to give the impression
that it is founded on a different species. I strongly suspect that the type of ferrn-
ginosus is a rubbed example of Anopheles crucians, which was described from the same
locality. Say's description of his Culex quinquefasciatus agrees very well with the
species which I have identified as Culex impiger Walker.
maculipennis Meigen. I strongly suspect that this European form is identical with
our Anopheles quadrimaculatus Say, but this point can not be settled definitely at
present, owing to the lack of any European specimens for comparison with ours.
nigripes Staeger. This European species should be readily recognized by its
unspotted wings.
albimanus Wied. Differs from our other species by the snow-white apices of the
tarsi.
Anopheles pictus Loew is evidently a synonym of .4. crucians Wied.


Our recognized species of Anopheles and their synonyms may therefore be listed
as follows, the synonyms indented:


rucians Wied.
pictus Loew.
? ferruginosus Wied.


pundwipennis Say.
hiemalis Fitch.
quadrimaculatus Say.
? maculipennis Meigen.


I,


CY





:.




.... ... ........ ... :. .... ... ............
... .. :: :i ... ... .. ." : .. :F ".. iEiE: i; .. ...... ... ..... ......
f-^ft
22" =":== ==";
23 '** "- "^
.... ::::'NE:IitE:i""
: ... = .. .. .. :...."


IV.-G-rNwf PSOROPHOUA.
Our single pies is of at yellowish color, usually varied with brown,Me..
the tarsal joints whit. It is onsiderably larger than :any of our otber'. i
yellowish or brown mosquitoes:
<7fnia Fahr.
roarrrn* Walker.
111foh'nlhis W iet-d.* "":
? r:bidu:lDesv.
VS-GENUS MusaARuINUs.
.T
(iOur tinre speries airs iyiigithe largest in this family, and are not known b:t11
north o1f tlin Distrivt. of Co(nliia. Theyi may be separated as follows:
All lanrei anirkti4 w it-i w iti- --........................................ ru
H l i ~ t b .'. .... .... . x




'in,.t1 tr-si tilnalt- irketl witl white -----------------------portorteu:Biie ea.-
Nomne tof t e tasi a.rkeI withl whit.e-.............................. ]AMn ao M h J |b
...=. .=:...




VI.-GENUIs AEDERS. :::..
(tur two .ipetis art-r among the smallest of our mosquitoes, and have a p.
linr ,wnisli grInl olri. l a. They i ay be distinguished asd follows:
'linor1ax niar-kel with a ieian violet blue stripe-------------a................. pphiriw .iiii
Tinorax Ilt-itute i f imnttl a tri e .........................-------------------------------- 0. i
..:. .:: .: .. ....! *
T11E BIOIA)<(!Y OF (ULEX. WITH REMARKS UPON SOME OF THE SPBOSBB-M

It is tolirabla.' certain i that the life.round of all of the species of 6.th.e .i;
V .- j_ . ......... .. "
tnr itis (sulex i rartically- the same. Theyf will differ more or les in-" :. Hj
th ni charnct'r of t(he water ii which they preferafbly breed, and differ...- h::'"
ing iin this respect, they will differ also in some degree in their pr. X 4
ferred food,I which consists of all sorts of aquatic micro-orgaism a .^
Down to the tiet' when the writer published his account of OW..h'r
Pit/liqrN, iil Bulletin No. 4. New Series, of this office, there was ot ,
in any 1 published work a thoroughly satisfactory figure of a well ip l
deterni ned species of mosquito from the United States, or of it,'
earlier stages. The statellments quoted in the text-books and mnuials
~- ** c"': !i './ t ,"-!"!




dated back in general to the time of Reauniur-more than one" hiuna .^
dred ad(1 fifty years ago. Reaumur's observations were made in the"',
.. ... .. ..
month of Maay upon a species (uiecxp/pdenn) which does not occur a.:
North America. and the observations were all made at Paris, so that ^.` i
statements as to the duration of the insect in any stage would ..be ..i
incorrect even for the same species in a farmer or colder locality. ^
% '..............
Tie following account of the life history of C'ulea pungeo (fig. 1) h .!a ..
quoted froint the writer's bulletin above cited: **i;
L&f Afurwy 4't ( ir. ])ti/.e..t.%-The operation of egg laying wS:...ii.
nlot observed, but it probably takes place in the very early mornig
horlirs. Thee eggs are laid in the usual boat-shaped mass, just as toa :::::
Of (t fa; i, g rals.t4 dlescribedi by R6eaumur. We say boat-shapednu &HUB
ledattifse that is thge ordinary expression. As a matter of fact, howeing.i...'...
the egg uimssesi are of all sorts of shapes. The most common omo:gu a

-.a
ttn taold atn fh istn n sgwu ':, =.!!
im~rr(,' evn or hesam spcis i a 'ame orcolero( "," ":::' 'i'! i:i .* hi:tS;:
Th fl~in :(out fth lfehstryo Cle uje fi.1) .: ,:..j;1-:IsF




r

28

Ithe pointed ellipse, convex below and ('concave above, all the eggs per-
*pendicular, in 6 to 13 longitudinal rows, with.i from 3 or 4 to 40 eggs in
a row. The number of eggs in each batch varies from 200 to 400. As
.seen from above the egg mass is gray brown; from below, silvery
PJ:white, the latter appearance being due to the air film. It seenis
Impossible to wet these egg masses. They may be pushed under
water, but bob up apparently as dry as ever. The egg mass separates
rather regularly, and the eggs ;ire not stuck together very firmly.
After they have hatched the mass will disintegrate in a few days, even
in perfectly still water.
The individual eggs are 0.7 mm. in length and 0.16 mm. in diameter
at the base. They are slender, broader and blunt at bottom, slenderer
Sand somewhat pointed at tip. The tip is always dark grayish brown in





I *i













FIG. 1.-C'ulex pungens: Egg mass, with englarged eggs at left and young larvae below-enlarged
(original).
color, while the rest of the egg is dirty white. Repeated observations
show that the eggs hatch, under advantageous conditions, certainly
as soon as sixteen hours. Water buckets containing no egg masses,
placed out at night, were found to contain egg masses at 8 o'clock in
the morning, which, as above stated, were probably laid in the early
morning, before daylight. These eggs, the third week in May, began
to hatch quite regularly at 2 o'clock in the afternoon of the same day
on warm days. In cooler weather they sometimes remained unhatched
until the second day. If we apply the evidence of European observers
to this species, the period of the egg state may be under twelve hours;
but there is a possibility that they are laid earlier in the night, which
accounts for the fact that sixteen hours is the shortest period which we
can definitely mention.






24


The larvas issue from the underside of the egg namO,.....
extremely active at birth. When first observed it is easy toA M ..
San error regarding the length of time which they can rem i
water, or rather without coming to the surface to breathe,
striving to come to the surface for air, many of them will std1
underside of the egg mass and remain there for many minute.6:::
altogether likely, however, that they get air at this point thu
eggs or through the air film by which the egg mass is surroundsumt
that they are as readily drowned by continuous immersion M aIA
older ones, as will lbe shown later. ii*
.... .. ... :!!: :: :i!.. ::. ii"^^^ iii
One of the first peculiarities which strikes one on oserving ta
.II ~ ~.. .i :" !ii. ii.....i[
newly-hatched larvae under the lens is that the tufts of filaments. wId.S
are conspicuous at the mouth are in absolutely constant vibration. 1 I
peculiarity, and the wriggling of the larvae through the wats, anl::
; : ];i *:'? ..





... . ... .


.-' -'--" ... : ... ...







Fli. 2.-t lcpunges: Head of larva from bellow at left; same from above at right-reatly enlaqgd
(original).

their great activity, render them interesting objects of study. In gen":: .
eral the larvae, passing through apparently three different stages, reachI
maturity and transform to pupa- in a minimum of seven days. Whea
nearly full grown, their movements were studied with more care, as
they were easier to observe than when newly hatched. At this t h
the larva remains near the surface of the water, with its respiratory
siphon at the exact surface and its mouth filaments in constant vibr- ;;
tion, directing food into the mouth cavity. Occasionally the larva ;
descends to the bottom, but, though repeatedly timed, a healthy indie
vidual was never seen to remain voluntarily below the surface morb .
than a minute. In ascending it comes up with an effort, with a serh-:..
of jerks and wrigglings with its tail. It descends without effot, b t '
ascends with difficulty; in other words, its specific gravity seems to be.: ..
greater than that of the water. As soon, however, as the repiratr

.:i:: : .. ".


"! .. .......[E
.. :::: E m E
":: ::. ""EE.'
: :.. ....... :
.. ...:: ............






25
siphon reaches the surface, fresh air flows into its tracheae, and the phys-
ical properties of the so-called surface film of the water assist it in
maintaining its position.
The respiratory tube takes its origin from the tip of the eighth ab-
dominal segment, and the very large trachea can be seen extending to
Sits extremity, where they have a double orifice. The ninth segment of
the abdomen is armed at the tip with four flaps and six hairs, as shown
in fig. 3. These flaps are gill-like in appearance, though they are prob-
ably simply locomotory in function. With so remarkably developed an
Apparatus for direct air breathing there is no necessity for gill struct-
ures. Raschke1 and Hurst2 consider that the larva breathes both by
the anus and by these gill flaps, as well as by the large tracheae which
open at the tip of the respiratory tube. Raschke considers that these
tracheae are so unnecessarily large that they possess a hydrostatic
function. The writer is inclined to believe that the gill flaps may be
functional as branchial structures in the young larva, but that they
largely lose this office in later life.
After seven or eight days, at a minimum, as just stated, the larva
transforms to pupa. The pupa, as has been repeatedly pointed out
*ith other species, differs most pronouncedly from the larva in the
great swelling of the thoracic segments. In this stage the insect is
lighter than water. It remains motionless at the surface, and when
disturbed does not sink without effort, as does the larva, but is only
able to descend by a violent muscular action. It wriggles and swims
as actively as does the larva, and soon reaches the bottom of the jar
or breeding place. As soon as it ceases to exert itself, however, it
floats gradually up to the surface of the water again. The fact, how-
Sever, that the larva, after it is once below the surface of the water, sinks
rather than rises, accounts for the death of many individuals. If they
become sick or weak, or for any reason are unable to exert sufficient
muscular force to wriggle to the surface at frequent intervals, they will
actually drown, and the writer has seen many of them die in this way.
It seems almost like a contradiction in terms to speak of an aquatic
.- insect drowning, but this is a frequent cause of mortality among wrig-
|| glers. This fact also explains the efficacy of the remedial treatment
which causes the surface of the water to become covered with a film of
oil of any kind. Aside from the actual insecticide effect of the oil, the
larvae drown from not being able to reach the air. The structure of the
pupa differs in no material respect from that of corresponding stages
Sof European species, as so admirably figured and described by the older
writers, notably R'aumur and Swammerdam and needs no description
Raschke, Die Larve von Otlex nemorosus, Berlin, 1887.
SHurst, the Pupal Stage of Culex, Manchester, 1890.
S Even Bonanni, in 1691, gave very fair figures of the larva and pupa of a European
: species. Micrographia Curiosa, Rome, MDCXCI, Pars. II, Tab. I.

iL .





A V .:. .. .. .... : i :
aA

26r
in view of the care with which the figures accompanying l
have Ibeen drawn. The air tubes no longer open at the and'a4
bIody, uit through t which it results that the pupa remains upright at the su
of with the head downward. There is a very apparent obej::...
reve.rsul (if the pIsitionm of the body, since the adult insect iS us.,
the thorax atnd titeds the floating skin to sWpport itself while iswFIJ
are expandinlig.
In general, th1 adult insects issue from the pups that arew.Sm
W.. ........:... ... ......



'A:
.. !iiiiiiiri
























FI, i t o 1 i w*. ittijitit Fi i I -gri jrw u larva a t Ilef t, Ipu pa a t righ t-enlarged (original). .:|
0](I. is :"iv"s what, is probably the .inimui generation for" th ":
species as ten day-s, namivly, Sixteen to twenty-four hours for th~eg(
Stvii11 day-s for the larv-a, anid two days for the pupa. The nidol
S(----n.r on. the. first da were invariably iales. On the seocday."A
" ": "!"? : i:* ::::











tjhpy (,,*,t, majority wIere males, but there were also a few females. ....s S.....
prep) n denan ve Of m1atles con tinted to bold for three days; Lii '.l~t_!
fenmale's were in the miajorityN. In confinement the male die~d:lliisJI
several11 lived for fouir dayNs,, but nione for more than that period,.
f, o ...... .
"ji- -" ol gm w.:..:a :'














S..... ..... ::
Fi'.. : .--t ub: jiIII:fe.i.." Fill-grown larva at kift, pupa at right---nlarged! (origina~l).. ,..
01(1. 'lhiis gives what is probably the minimum generation for th ....,!is
l) .is:s ttii (laysq na=me1ly, sixteen to twenty-four hours for the egg,':i
seven] days for the larva, and two days for the. pupa. The individa,:a
eme.rging ,,n the first day were invariably males. On the second day ':,,,;,
tl,.' great inaj,,rity were males, hut there were also a few femls flua .::;:,
prepo,,dhrui,', of males continued d to hold for three days; late thi: '!
fv.,,alhs were in the majority. In confinement thle maln diedquic ily;
several live d for four days, b~ut none for wore than that period. Thu,::
females, however, lived for a much longer time. Some were kep ===.==========


'C:.. ..? i




SW -


27

without food, in a confined space of not more than 4 inches deep by 6
across, for three weeks. But one egg mass was deposited in confine-
ment. This was deposited on the nmrning of l1e 30 by a female which
issued from the pupa June 27. No further observations were made
|upon the time elapsing between the emergence of the female aid the
:laying of the eggs, but in no case, probably, does it exceed a few days.
The length of time which elapses for a generation, which we have
Just mentioned, is almost indefinitely enlarged if the weather be cool.
SAs a matter of fact, a long spell of cool weather followed the issuing









.






p-n












FIRG. 4.-Culex pungeizs: Female above, male below-enlarged (original).

of the adults just mentioned. Larvae were watched for twenty days,
during which time they did not reach full growth.
The extreme shortness of this June generation is significant. It
|accounts for the fact that swarms of mosquitoes may develop upon
occasion in surface pools of rain water, which may dry up entirely in
the course of two weeks, or in a chance bucket of water left undis-
turbed for that length of time. Further, the shortness of this genera-
tion was, while not unexpected, not at all in accordance with any


.; ... "
::.
ii;-"






28


published statements as to the length of life of any
quite of any species. But these published statements, as
shown, were nearly all based upon observations made in.a:::...
climate and in the month of May.
Renarks on other species of (Alex.-The writer is inclined to:.:
that Cu(lr. tfindiriynekus (fig. 5) is more or less specifieally:thmil
e(most mosquito of the Atlantic seaboard; that is to say, it :
mosquito) in this part of the country which is able tobreed anliat
to breed in the brackish swamps which are occasionally oer lllnd
high title. It has been found by Mr. C. W. Johnson at Ati44
Anglesea, and Atlantic City, N. J.; by the writer at Far B lskwii6tlj
Amergansett, and on the beach at Staten Island, New York; b


... "... :.... ::": .... : ...... i




.10














FIG. 5.-Cul".x la-.iiihiychu: Female, showing the short palpi which
distinguish Oie [rum Anophels; toothed front tan&]l claw at bright i
enlarged (original). ;" i
Barber at Chesapeake Beach, AM.. and again by Mr. Johnson at Lf
Augustine and Charlotte Harbor, Fla. Other species, like NkauRexpm
9114^ are seen at seaside resorts, but it is probable that these bree
back of the. coa-st in fresA water. This difference in breeding habit:ifif 's
I


.......
.. .







V & :''. ,, "":::






~distinguihbethe thei frumAophkn toothed frontutaoes awd ate ringh-leg~

Barber atd hswapeak Back th, bluffs and ag e aine byn Mr .JhsnatSttui
A. ). Hopkins states (Bulletin 17, new series, Div. Entolk...




Agric.) that what is probably this species apparently breedi hab.iti. .
q: ,, :" .
** :::,::; I
ver make on-C. t.mhe east co: oFeStaten Island.th Ther p eoplehic thpr..e
ditig ishbtwengs tuhe brow n-peleggtoted mrosqutoe tanda the ringtu- :Ii

pounds atd swampsak backthe bluff, and thegattey r. beingo Ct. h


rhytnguwich brteedsin the brackishge marshutes belo the bluffs. Da,

A. 1). Hlopkins states (Bulletin 17, new series, Div. Entom.;, DtL;,
Agric.) that what is probably this species apparently breeds in Wn.:!,
:4 ii". ddiii..

eIt:.EE : J[E~""..




. -r Sm l


r 29
Virginia in pools and small streams fed from coal-mine drainage, the
Water of which contains a large percentage of sulphate of iron.
SOzde impiger has been found by Mr. Pratt, of this office, breeding
iin privy vaults in Alexandria, Va., and this species is likely to be the
!one found usually in such places where the water is fouled with decom-
.posing or excreted animal matter.
Odex taeniatus is said by Dr. Veazie, of New Orleans, to be the
so-called "day mosquito" of New Orleans; that is, the form which
flies and bites in the daytime. This statement is corroborated to a
certain extent by Dr. St. George Gray, of St. Lucia, British West
Indies, who writes, under date of August 12 last:
f have made some observations on the hours at which the different species are
most industrious, and find that most mosquitoes have regular feeding times. For
instance, C. tIniatus is very vigorous and troublesome in the early afternoon (between
noon and 3 p. m). Then she usually takes a rest, and renews her attacks at 9 or
10 p. m. During the morning it can be found resting on walls and clothing, particu-
larly dark-colored clothing, and is easily caught.
The distribution of the species of Culex in the United States.-In
preparing Bulletin No. 4 the writer was at pains to borrow all of the
mosquitoes from the collections of such entomologists as he supposed
had saved specimens in this family and placed them in the hands of
Mr. Coquillett for study. The material received was not large, since
mosquitoes are difficult to preserve satisfactorily in a collection, and it is
an inexplicable fact that as a rule collectors do not save such extremely
common things as mosquitoes. Yet he was able from Mr. Coquillett's
work on the specimens received and on those already contained in the
national collection at Washington to show several interesting points.
As is the case with many other species of Diptera, most of the differ-
ent forms were found to be very widespread. The whole group has
little or no faunistic value; that is to say, different climatic conditions
and other environmental factors do not limit the range of the species
as they do with those of other groups. It was thus found that some
of the commoner forms, like C. consobrin us, C. excitans, C. perturbans,
and C. posticatus, and C. pingens, were found almost all over the
country, from New England to Texas and even to southern California,
so that in almost any given locality in the United States one would be
able to find all of these common species of Culex, with two or three
species of other genera and possibly two or three other species of
Culex. Since the publication of the bulletin (No. 4), other localities
of distribution have been ascertained, and the following list indicates
such actual localities as have come to our notice. Persons interested
will observe several points worth noticing in the list which follows.
Certain species seem to be rare, while others are very common, in
addition to being widespread. It seems from the list that Culex con-
sobrinus is a more northern form; that is, it comes nearer being
t-restricted to a boreal habitat than any of the other species. It is one




" ~ ~ ~ """:"- "::: :h "1 "
. :...:. .... .. : ... .. :::::: ..
:... ...*. ..
*L .i .


8 0 .............

of the two "pecies which -we have from Alaska.. The o
form which liias been determined, namely, C. imniger, extmbi
to New Mexico, Georgia, and the island of Jamaica. ...1
('.r fipp.wf Di.a woOrding to Mr. Theobald, has a wide .*o....*
subtropical distribution, occurring in West Africa, IndI
..... ..... .. ... ..i
Europe, and East and West Indies, but never in'the north k .
cold tempip-atte Zons.
CULICX CONOB)RINUS l4 \'. 2:;;;"
Habitat: Whitet Mountainsf, N. H.; Beverly, Mass., September (28 N.
Catskill Mountains, Greene County, N. Y., 2,500 feet (Howad); i7M
March 21, April 29, May 6, October 16 (Naeon); St. Anthony -Piefij{
April, May, oin rniw (Lugger); Saskatchewan River, British*Amerksi U..-
IDakota (Nat. Muis.); Lincoln, Nebr., May, September (Bruner); Mom.is,.
(Nat. Mu .); Ls Angeles, CaL., February (Coquillett); Argue Mri i!WU
Cal., April (Nat. Mus.); Santa Fe, N. Mex., July (Cockerell); New Oua,..|
La., November (Thayer); Ottawa, Canada, May (Howard); S it I.l.
(HIolnies); Trenton, Ontario, May 24 (Fletcher). ..
(Ct'LEX EXITANS Walk.. .""
Habiitat: New Bedford, Mass. (Johnson); Lincoln, Nebr., May (Bruner); .il'.
F%, N. Mex., Jul" (Cockerell); Laggan, British Columbia (Wickham). :
Ci'LEX :X\Ir',ci.\.NS Walk. .
Hal)itat: Ithaca, N. Y., July 14 (Comstock). ,:
CUL.EX FASCI .vrrs Falir.
Habitat: (ermgia, .August (Coquillett); NatchIitocx-hes, La., October 6 (Johno);.
Isle ,,f Pinies, West Indies (Scudder); Kingston, Jamaica, July 13 (Jolaou
New Orleans, La., November (Thayer); eastern Texas (Woldert); Ont.::.
(Lazear).
CULEX ]MPIGER Walk. ."
Habitat: White Mountains, N. H.; Beverly, Mass., May 24, June 2 (Nat Ma.),
Ithaca, N. Y., July '. and 17, August 28; Wilniuth, N. Y., June 10 (Com.:k)I
Saskatchewan River,British America (Nat.iMuis. ); Minnesota(Lugger); Io a i
County, Va., August 26 (Pratt): Tyrone, Ky., July 14 (Garman); GeoM.]
(Nat. Musp. ); Mesill.a, N. Mex. (Cockerell); Isle of Pines, West Indies (Swdder)i !
Portland, Jauiaica (Johnson); District of Columbia, September 12 (Barber); t
Alexandria, Va. (Pratt); Ogdensburg, N. Y., June 3 (Howard); Middle.owa, :.
Conn., June (Davis); Ottawa, Canada, May 31 (Howard); Chats Rpid s Qe :
bee, May 24 (Fletcher); Buckeye, Wash. (Nat.. Mus.); Stikine River, DldiaI
(Columbia (Wickham).
CULEX PERTURBANM Walk.
Habitat: Lakeland, Md., August 8 (Pratt); Virginia, August 17 (Pergande);Ti&
Island, Fla., 5May 12 (Johnson); Texas (Nat. Mus.); Bayamon, Porte io
January (Busck); I)istrict, of Columbia, September 1-5 (Barber); St EhoV..I
June, July (Pratt); Cuba (Lazear). :
C'LEX POSTIC'ATUs WVied.
Habitat: Montgomery County, Pa., July 17 (Johnson); Texas (NaLOM ..a)a.,
Loudoun County, Va., August (Pratt); Roanoke, Va., October (TIhayr); :DI:.,.
trict. of (?lumbia, June 10 (Barber). ::.........
(.'LEX I'L'N(EN WVied. .L .;F* '.i '
Habitat: White Mountains, N.H.; Beverly, Mass., Sep em er 5.;,lbll
Man., September 16 to November 5; Boston, Mass.; Baltimore, Vd., Wil
her 5 (Nat. Mus. ), November 26 (Lugger); Charlton Heights, Md., Nei-t, B
(Pratt); District of Columbia, January 30, March 5, May and 15, J6 anlid ,
July 11, August, October 10, 15, 25, and 31, November 4, 8, 13, l% .iix4j







31


December 23 (Pergande); Ithaca, N. Y., Mar 29, July 17, August. 29 (Corn-
stock); Illinois (Nason); Minnesota (Lugger); Lincoln, Nebr., Sr'pt.nuler 20
(Bruner); Lexington, Ky., Noveiln-br 10 ((Garnian ); New Orleans, La., Dectin-
ber 17 (Howard); San A-ntonio, rex., May 5 (Marlatt); (heorgia, August
N. (Coquillett); Portland, Jamaica, (Johnson); Mexico City (Barrett); District
of Columbia, August 22, 28, September 1 (Barber); Jackson, Va., 0ctoler
(Thayer); Woodstock, Va., June (Pratt); New-port News, Va., (-Otolter
(Thayer); Stillwater, Okla., June (Bogue); Plhiladelphia, Pa., (Woldert); New
Orleans, La., June (Veazie); eastern Texas (Woldert); Summit, N. J., May
(La Rue Holmes); Middletown, Conn., June (Davis); Cuba (Lazear).
CUtTLX SIGNIFER Coq.
Habitat: District. of Columbia, June (Coquillett), May, August (Barber); St.
Elmo, Va., June 4 (Pratt).
CULEX STIMULANS Walk.
Habitat: White Mountains, N. H.; Beverly, Mass., June 2, July 9; Cambridge,
Mass., May; Jamaica Plain, Mass., August 25 (Nat. Mus.); Baltimore, Md.
(Lugger); Illinois, August 1, September 15, October 5 (Nason); Agricultural
College, Mich. (Gillette); Saskatchewan River, British America (Nat. Mus.);
Lincoln, Nebr. (Bruner); Colorado (Nat. Mus.); Ithaca, N. Y., June 13, 18, 29,
July 14, August, 28; Wilmuth, N. Y., June 10 (Comstock); Georgia (Nat. Mus.);
Bladensburg, Md., May 27 (Barber); St. Elmo, Va., June 5 (Pratt); District of
Columbia, September (Barber), June 10 (Miss L. Sullivan); Ottawa, Canada,
June 1 (Howard); Ogdensburg, N. Y., June 3 (Howard); Rochester, N. Y.
June (Ewers); Summit, N. J., May (La Rue Holmes); Middletown, Conn.,
June (Davis); Mesilla, N. Mex., October 26 (Cockerell); Tacna, Ariz., April 13
(Hubbard); Juarez, Mexico, May 12 (Cockerell); Summit, N. J. (Holmes).
CULEX T.ENIATUS Wied.
Habitat: New Orleans, July (Veazie); Cuba (Lazear).
CULEX TZ&NIORHYNCHUS Wied.
(Not the Culdex tniorhyjnchuis Wied. of Arribalzaga.)
Habitat: Maine, August; Beverly, Mass., June, September 15 (Nat. Mus.);
Avalon, Anglesea, and Atlantic City, N. J., July 10 to. 29 (Johnson); Far
Rockaway, Long Island, N. Y., August 30 (Howard); District of Columbia
(Pergande); Georgia (Nat. Mus.); St. Augustine and Charlotte Harbor, Fla.,
July; Portland, Jamaica (Johnson); Chesapeake Beach, Md. (Barber); Balti-
more, Md. (Thayer); Plymouth, N. C. (Thayer); Galapagos Islands, February
1-4 (Snodgrass).
CULEX TARSALIS Coq.
Habitat: Argus Mountains, Cal., April; Folsom, Cal., July 3 (Nat. Mus.).
CULEX TRISERIATUS Say.
Habitat: White Mountains, N. H. (Nat. Mus.); Delaware County, Pa., June 12
(Johnson); Washington, D. C., May 5 and June 10; Loudoun County, Va.
(Pratt); Near Baltimore, Md. (Thayer); Roanoke, Va., October (Thayer);
Middletown, Conn., June (Davis); New Jersey (Woldert).

THE BIOLOGY OF ANOPHELES, WITH GENERAL REMARKS.

SSo far as the writer can ascertain, no detailed illustrated account of
Sthe early stages of any species of Anopheles had been published before
Shis paper in the Scientific American, above referred to.' He con-
Sceived it to be nearly as important that the malarial-bearing mosquitoes
should be readily recognized in their early stages as in their adult con-
.;;dition. He was very fortunate in April of the present year in being

SSee appendix.






32


able to secure a large number of gravid females of AnopAdwi! :1
macul d.f u Say through the abundance of this species near te.:
one of his assistants, Mr. Pratt, in Virginia, a few miles fMb!
ington. Mr. Pratt was enthusiastic and assiduous in collectingi
adults, and th-tse were kept in confinement and their offspring" ii'..
in large water jars during April and May, 1900. It may be
here that this species is without doubt identical with the Auic
Anyhes. n witd;/,cfnis nMeigen, a fact which Mr. Coquillett .haulwa: y "
strongly suspected, although he had no European material with wli6i
to compare our American specimens. Dr. W. S. Thayer sawA. Mad.....
lUprn,;dx in Grassi's laboratory in Italy, and on his return to tai conis-









4













F1i. e -J\in/.iqfl(K qu adrhoaiw In fitaR: Aduhl; maler ai left, feirale at right-enlarged (oriusai).
try told the writer that he thought the two forms identical. The o
(j Lestion has now been definitely settled by Mr. F. V. Theobald, of
England, who is monographing the mosquitoes of the world for th& i
British Museum, and who writes us under date of May 28, 1900,-th:aft
he has studied a large series of A. quadrimadulatu. received fro*i
Canada and that "they exactly tally with A. macvUpenniai#."
LIFE HISTORY OF ANOPHELES QUADRIMACULATUS.
TIE ADULT.-The accompanying illustrations (figs. 6,7,8)wllashw;
very well the general appearance of the adult insect. It is a rather.






33


lrge mosquito and is very wood-thirsty. It is attracted to the house
i numbers. The differences between the males and females are well
brought out in the illustrations, and the striking feathery antennae and
irplpi of the male render it very conspicuous. The wing markings and
|'the color of the palpi differentiate this species from our other species of
|Anopheles, and the long palpi of the female at once distinguish it from
\all species of Culex.







FA









FIG. 7.-Resting positions of Culex (at left) and Anopheles (at right), enlarged (redrawn Irom a rough
sketch published in the British Medical Journal).
Resting po8ition.-Owing to the publication of a field sketch made
at Sierra Leone by a member of the Ross expedition, and which is
here reproduced, the writer has been much interested in watching the
resting positions of the adult insects. He finds that when resting upon
a horizontal surface-such as the ceiling of a room or the covering of
the breeding jars-the insect clings with its four anterior legs in a
nearly perpendicular position, its beak thrust forward toward the sur-
face to which it clings. The hind legs are frequently in motion, but
as a rule hang downward with more or less of a bend at the knee joint
(femero-tibial articulation). When resting upon a perpendicular sur-
face, however-such as the side wall of a room or the side of a breeding
jar-the body is held only at a comparatively slight angle from the
surface. Sometimes it is nearly parallel with the surface. At other
times it assumes an angle of 100 to 200 (occasionally even as great
F\an angle as 300 to 400), the proboscis being held nearly in a line with
:~the body. Here again the insect supports itself by the four anterior
legs, the hind legs dangling down with more or less of a bend at the
: 3949- 3







84


.. .. ......... "...: ..
-... .......,!h!!i:
.::: .. ..: .:::


knee. This position is common to both males and females, bail
treated at fig. S. When the body is held parallel it will .gei"E
found that one of the middle or hind legs has been broken off. ::
are very delicate and readily. break.
1I ":! ..I


-[I


$S


I .'. E:::.. .. E

\ :- :
I!:"..'[[: ",;
., i.!._ .::: .:.1
Fir.. S.-Actual resting positions of A. quadrimacidalus on S a horizontal ceiling and oa dftIu1
drawn from life-enlarged (original)....,

The writer has taken the liberty of having fig. 9 engraved, from a: |
drawing sent him by Mr. C. 0. Waterhouse of the British Museum.
Mr. Waterhouse made the drawing himself and wrote: "Whatslr"i .3
I "R': .".:. ...
.. :........ :: :::











lar. hui mpba.ked." .

XAt, offeinal,.--The peculiar hum of the mosquito is welllkriwa
There is a distinct difference between the hum of AnopAelde .gapiijl.
.: . ... ... w;;






35


* folau and that of the common species of Culex in that the former is
Noticeably lower in tone. The note of Culex as it approaches the ear




















Fie. 10.-Anopheles quadrimaculatus: Group of 44 eggs deposited by a single female as
a they appear resting naturally on the surface of the water-enlarged (original).
is high in pitch; that of Anopheles is certainly several tones lower
and of not so clear a character. In quality it is something between the
buzzing of a house fly and the note of Culex. Mr. Pratt states that he
can at once distinguish the two genera in
this way as he is sitting reading in the
House, and the writer feels quite sure after .0
listening to them in breeding jars that the
statement is correct.
These observations have been made with
an abundance of material, nearly 100 adults B
having been under observation.
THE EGGS.-The well-known and often-
mentioned boat-shaped masses of eggs of
Culex are not even remotely resembled by
Sthe Anopheles ovipositions, and the indi-
Svidual eggs are equally dissimilar. In the
accompann io (g 1 th FIG. 11.- Anopheles quadrimaculatus:
..accompanying illustration (fig. 10) the egg Egg from below at left, from above
Smass of Anopheles is illustrated for corn- at right-greatly enlarged origin .
prison with fig. 1. In Culex from 200 to nal).
400 eggs are laid in a mass ordinarily shaped like a pointed ellipse, con-
Viex below and concave above, all the eggs perpendicular, and stuck




i:ii.% :iil:;:i .:.:. : ...: .. : .... .. .:.: .: :: ..:i i :. !.. !!i .. iii.... ..
=~.. ....... :
..... .. ......
": .E :: .lE : " : [ ..: .. . . . .


closely together at the sides by some gummy secreton, *
in rows. The mass with Anopheles, however, islandd
surface of the water, each egg lying upon. its. side iiit
placed upon its end as in the egg mass of Culex, They aS:n.J1 |||
together except that they naturally float dose to each oth
are from 40 to 100 eggs in each lot. In Cuds psnga tl
egg is 0.7 mm. long and 0.16 mm. in diameter atit'
slender, broader, and blunt at the bottom, slenderer and M
at the tip. The tip is always dark grayish brown in-o .or
rest is dirty white. The egg of Anopheles when seen furm
of a rather regular elliptical outline, the two ends havig:::ie
the same shape; seen from the side, it is strongly convex'; i|7
nearly plane above; seen from below, it is dark in colo....'ii.
examined with a high power is seen to be covered with p
hexagonal sculpturing. At the sides,'in the middle, the:::.r
clasping membrane with many strong transverse wrinkles. ..:..
above, the egg is black except for a clasping membrane whii.....id.y



.. .. .... ....: .:: .:: ."
,' ......,..::.::+ i!:',++++++++m i:'.... ..... ............




... .' ...'....


PiG. 12.-Anop~heka qaudrbimaulalua: Newly hatchied larva--greatly enlarged (*m)

meets on the middle line in the middle third of the body, buit redreuiCV
',, : .:: 5 ,:"" "* := ....** .; 11





the extreme sides for the anterior and posterior thirds. Attack Sp#|
the color is lighter, with a group of from 5 to 7 minute dark circular
spots. It is 0.57 mm. long. Eggs laid April 26 hatched Ap"I S
: ::: ... .. ... d : i .ii : .. ...!ii :






Others laid May 13 and 14 hatched May 16 and 17. ...
THE LARVA.--The larva is quite as unlike that ofOei C rnm.:
is the egg. It differs in structure, in its food habits, and in
tomary position so markedly that it can at once be distinguished WE.f.
the utmost ease. The larva of Culex, it will be remembered
to the surface of the water to breathe, thrusting its breathing p|
through the surface layer and holding its body at an angle of 0C..001
45 degrees with the surface of the water. While in thisii '
mouth parts are in motion and it is taking into its alimenta y. .i
such minute particles as may be in the water at that depth,bu::
are naturally few in number and the larva descends at f e i .
vals toward the bottom to feed. The want of oxygen, hwt
it to wriggle up again to the surface at very frequent inrd .
: : ;:: i;: = i









'~IH
spot. ] is .57mm.long Egs lid Aril26 htchd K :,. .".iiI
H I" . . : i .: : i : : i i






"87

speific gravity seems greater than that of water, so that it reaches the
srface only by an effort, and the writer has already pointMd out in the
Scse of C. pun gen.s that when the larva becomes enfeebled and is not
::*strong enough to wriggle up to the surface it drowns. Feeding as it
des at the bottom upon the heavier particles which sink, its specific
nvity is explained. The larxa of Anop1&e.l quadrimaculats, how-
ever, habitually remain., at the surface of the water. Its breathing
t:ube is very much shorter than that of Culex and its body is held not
at an angle at the surface, but practically parallel with the surface and
.'.Imniediately below the surface film, so that portions of its head, as
well as -its breathing tube, are practically out of the water. Its head
t* rotates upon its neck in a most extraordinary way, so that the larva





i"C
7













I!





FIG. 13.-Anopheles quadrirnaculat us and Culex pungens: Half-grown larva at left and in center, in
comparison with half-grown larva of Culex pungens at right (figure at left has been cleared)-
greatly enlarged (original).
can turn it completely around with the utmost ease and feeds habitu-
ally with the under side of the head toward the surface of the water,
whereas the upper side of the body is toward the surface. In this cus-
tomary resting position the mouth parts are working violently, the
long fringes of the mouth parts causing a constant current toward the
mouth of particles floating on the surface of the water in the neigh
borhood, which thus gradually converge to this miniature maelstrom
!..and enter the alimentary canal. The spores of algae, bits of dust,
minute sticks, bits of cast larval skins, everything in fact which floats,
follow this course, and, watching the larva under the microscope, they
j:in plainly be seen to pass through the head into the thorax until they







are obscured by the dark color cf the insect's back. a
large a fragment to he& swallowed with ease clogs the month.:::
times it enters the mouth and sticks. In such caes the h a lA.
larva revolves with lightning-like rapidity and the fragniot UtMis
always disgorged, although sometimes it is swallowed with 8an6
effort. Since the Anopheles larva feeds only upon these light .
particles, its .4xpeific gravity is nearly that of the water iteNed
supports this horizontal position just beneath the surface it?'
comrnparative ease, and in fact without effort, the tension of their e 6
film itself a
hardly .need,
hold it. It nq IS:i' "
an effort in fetI ...
---- for the Anophelu ar'. 1
to descend (which lt:'
apparently n-erfls
does up to thea p .ei i
^^^^ )^^^of the fial ln
^p^^ jfl stage, except whe."1,
P 71n eeaalarmed), while it.
requires an e, te oi
for the Culex larva
to ascend.
Structurally.,: tiIe..
differences betweec
r izthe half -g.rown.t:
larva of Cndex and ::
Anopheles am w.e.l
shown at figs. 18,4,
and 15. The greia
size of the ho:
Culex, as cotint.d
SIwith the small hm:::
'W^ of Anopheles is"'
FRo. 14.--Figire at lop, half grown larva of Anopheles in feeding po- most strikingdifE&
thin, jui.st btenm.ath isurfaee film. Figure at bottom, half grown larva ence. The very .
of Ciultex in breathing losition-greatly enlarged (original). 1 o n g r pa t .,i" srIy
siphon (as Miall (calls it) of Culex contrasts markedly with the sho6t.?:.
one of Anopheles. The arrangement of the hairs is entirely difereai.
the branching of the hairs of Anopheles, as contrasted with the simp::iil
hairs of Culex and the little paired star-shaped (apparently b...ranchial:!
tufts on the dorsumni of Anopheles are entirely absent with Culex. Th I
flaps at the tail end of the body are similar in number, but are 6heki 1'
a somewhat different position.'..
_. .
.. r,.,,:H,,4: ii
I,: i "ii Ei.. ~ ii Eii.;
HI*:m.mn






89


The larvme first studied-those which hatched from the eggs on
April 30-grew very slowly for a number of days. This was partly
owing to cool weather in the early part of May, and partly, I believe,
to the absence of proper food. They were reared in glass jars of water,
with sand at the bottom and a willow twig rooting in the sand. As
above noted, they
swallowed every
small particle floating
on the surface of the
water, and the dark '
coloration shown in .
fig. 14 was largely i .\," "
due to the fact tha '
most of these foo& -
particles were dark -:- .
colored. About the
10th of May, the -
larvae having passed I
through two molts,
Sa small quantity of --( i J
P the green algae grow- /
I ing on the lily ponds _** _
on the Department
grounds was placed
in the jar.1 The larvae a
commence to thrive '
much better, grew
rapidly, and the gen-- .
eral color of the body
changed to g r e e n. f ,/
The description of
the habits given
above held well until /-
after the last molt --
preceding the change '
to pupae. In this final
larval stage, as shown
jin fig. 15, the diameter FIG. 15.- Anopheles quadrimaculatus: Full grown larva in feeding
of the thorax became position, seen from above (head reversed, in feeding position);
dorsal side of head above at right-greatly enlarged (original).
much greater in com-
parison with the rest of the body. The larva was less marked, more
inconspicuous, and altered its feeding habits to some extent. After
'These algae were studied by Mr. A. F. Woods, of the Division of Vegetable Phys-
iology and Pathology, who informed me that the larger part belong to a species of
: the genus CEdogonium, but that there was also quite a large amount of a species of
|,1 Cladophora, with some Spirogyra. There was also some of the blue green Oscilaria.


ijf.. k...





. ..... .:!:::ii[
.. ... ... .,;; ii:i

remaining at the surface of the water, feeding, as beo,
particles for some time, it would wriggle violently and i
bottom, where it would remain frequently as long as tw@
before reascending to the top. Its appetite was evidetlyUii4
that it was not satisfied with the floating particles, and when lb6.
to the bottom it mouthed the particles of mand, evidently
the slime on the little stones and frequently even picking
a large sand pebble and 'then dropping it again. In this sage i,
vidual which grew most rapidly remained only four days .
formed to pupa on the morning of the 17th, after a larval
sixteen days. The accompanying figures of the larve have b
with such care that detailed description will be un u r.
were drawn from life under the compound microscope. S.. ..
structures are puzzling, notably the organs occuring on the d
the abdominal segments, shown most plainly in fig. 15, and w
as though they might be spiracles until they are examined uaner tihti
power in the cast skin. The writer does not care to risk ano ud
of opinion as to their function, although possibly it is known, and
possibly occur in other aquatic dipterous larva. In the esrly ataguuot!
the larvae they resemble minute branchial tufts, but no tracheal aiHl
nection has been found. ,"'..
THE PUPA.-The accompanying figure (fig. 16) well refpresntstbisill








(o.ia ) .. .. ...... ....
J ..,,. ~........ iii..,... ......,!!i
:: .E ... E "::.... .. .........
.. " .. ". . .... .........
.' ". i ~ ~... ... .. .. ...... :.:.:.iii
i ~....: ... . ........iii
*.*!!..... ......
." .." ". . .. j :.. :: m : i~.. :i..
!-" : / / i:!ii!!:i!!!!!;;.. .....

IN,' / ... .........
IN I .N :. ,,.! i:: ii'iii

: ...:;: : :. ii" i.. ....
.. ... ..: ::" ;".:Ei
... ... ... ...R i
M : . ..... ... ..


FIG. 16.--PUPA Of Oex putagens at left; pupa of Anophdes quadrisaculahm at r !!! :i

differences between the pupa of Culex and that of Anopheles. ...... ....,.
stage the insects of the two genera are not so markedly differeBt-ll:11|:W|t
the larval stage. Structural differences need not be described, iftl i
are sufficiently shown in the illustration. The eye will at fiiiwi* AM
caught by the difference in position, the pupa of Culex .:eli::kW !-:'
more perpendicular attitude than that of Anopheles, and the:.11 11%i.11"Bil"
difference in shape between the respiratory siphons,. which
the thorax i instead of from the anal end of the abdomen, VM tOllc






41


I be noticed. The pupa of Anopheles is quite as active, when disturbed,
as is that of Culex. If one touches the near-by surface of the water
with the finger the pupa at once wriggles violently away, returning
shortly to the surface for air.
The duration of the pupal stage in Anopheles varies according to the
weather. Five days was the minimum observed during June, although
'several specimens remained in this stage for ten days. The adults issue
as do those of Culex.
The entire life round, therefore, of Anophele., quadrmaculatus in
i.the generation studied by the writer is as follows: Egg stage, three
days; larval stage, sixteen days; pupal stage, five days; making a total
period in the early stages of twenty-four days. It should be stated,
however, that during the early larval existence toward the end of May
there occurred nearly a week of cool weather, so that it is certain that
in the hot season in July and August the growth and transformations
will be more rapid. It will be remembered that the writer traced
Oule pungens through an entire generation in the latter part of June,
1895, in ten days.
NATURAL BREEDING PLACES OF ANOPHELES.
Having accomplished the preliminary work of studying different
stages of growth of Anopheles by breeding from captured females, we
were enabled to become familiar with the larvae and pupwe so as to
recognize them readily and it was then not difficult to find the natural
breeding places. The first breeding place discovered was in Maryland,
and the larva found there were those of what is probably A. puncti-
panis. They closely resemble the corresponding stage of A. quad-
rimaculatus except in the maculation of the head. A figure of the
head of this form is shown here (fig. 17) in order that it
may be compared with the corresponding figure of A.
quatdrimaculatus shown in fig. 15. This first breeding i/
place of Anopheles was a small permanent stream run- i
ning through the woods which had here and there broad- -"
ened out into little shallows, and in these shallows the -
Anopheles larvae were found resting at the surface of FIO. 17.-Anopheles
the water, and occasionally darting from one spot to pntipenis:
Head of full-
another. All of these little pools were abundantly sup- grown larva from
plied with algse, and from specimens brought in Mr. above-enlarged
A. F. Woods has found that they belong to the genus
Mougeotia. There were also many Diatoms present. The next natural
breeding place found was in pools about a disused spring in Virginia.
At the sides of the spring were several more or less permanent pools
of considerable depth (8 to 10 inches). Here the larvae of A. quad-
rimaculatus were found. Algae also occurred here and Mr. Woods has
Determined them as belonging to the same genus Mougeotia. The


........




F .. ... . ,. I......

..................
42 m H
temperature of this water was 18 C. The third locality
canal bed so nearly dried out after a season of drought that t
lay in rather small puddles. In this case the water was verry.out.
algw. of the genus Lyngbya were present. The temperature 1
water was 25" C., and the conditions were those of extreme
The first locality was discovered by the writer in company
Pratt and the second and third were found by Mr. Pratt.4* W
writer in company with Mr. Busck and Hospital Steward Smithi, l '
empty pupa skins of A. quadrimaculatuw in a dried up surfiaee IfJP4
the Washington Barraeks, at a time when malaria was very
among the troops. I am informed by Dr. Thayer, of Bdltim iir'|^^
Dr. Lazear found A. putwtipennis breeding in a stone quarry .i.. iiiii
Baltimore, in the summer of 1899. Ross found in India that while:iiiiii
species of Culex generally bred in vessels of water around the h Fen.!iiii
the species of the genus Anopheles bred in small pools of water c:m.......!!
the ground. This point was made the subject of a special investga :^ .
tion iby the expedition of the Liverpool School of Tropical Medieb:w::!1
N HI .. ...E d"" E
to Sierraw Leone. While Culex larvae were to be seen in almost ev ::er
vessel of water or empty gourd or flowerpot in which a little rain @r
water had collected, in only one case were Anopheles larva found int ...;.
such receptacles. On the other hand, they occurred in about 100::
small puddles scattered throughout the city of Freetown-puddles:
mostly of a fairly permanent description, kept filled by the rain, and
not liable to washing out during heavy showers. It was noticed also.
that the larve seemed chiefly to feed on green water weed.
In the interesting and important paper by Dr. J. W. W. Stephns:
and "Mr. S. R. Christophers entitled "The distribution of Anophelie
in Sierra Leone," published in the report of the malarial committee of
the Royal Society, July 6, 1900, it is stated that at Freetown nt'-:.
only do the larvae of Anopheles exist in the small pools in the rocks,
but also in the pools by the sides of streams and in certain smallH
drains, and that in the dry season, in the absence of the rock pools,
Anopheles breeds freely in streams and drains; also, in the dry season,
the adults exist in most parts of the town in dwellings, especially in
overcrowded native huts and native quarters, ready to lay their eggs
when pools appear. It is interesting to note, from this latter obser- J
nation, that the authors of the paper recommend the destruction of
dirty huts and the prevention of excessive overcrowding. Outside of
the city, in the "bush," Anopheles larvae were present throughout the
whole district. In the mountain streams, wherever there were suitable* |
pools, multitudes of larvae existed. In tracing the mountain streams,:::j
occasionally for a half mile or so, they found no larva, but then a s,
rock pool occurred, and there they were again found in numbersA .M. :i
Songo and Mabang they were able to detect Anopheles larva in .tb*firr
swamps. They were not present in the main swamp water on accat |
H Ni: 'i:: .l






43


-of the innumerable small fish, but were occasionally observed in small,
isolated pools on the mud, and were still more common in small pools
at the edges of swamps. It is a noteworthy fact that they did not
occur in swamp pools in such numbers as in the streams and rock
pools among the hills of Sierra Leone. "These rock pools would
appear to be the most suitable conditions for the breeding of
Anopheles."
The avidity with which Anopheles larve under observation in
Washington fed upon algam spores of the genera previously mentioned,
and the character of the breeding pools found here, indicate that with-
out doubt similar conditions will prevail generally in this country, and
Anopheles will always be found to breed most abundantly in fairly
permanent stagnant pools of water uninhabited by fish, but more or
less covered with green scum.
OTHER SPECIES OF ANOPHELES.

As appears from the synoptic table on previous pages, we hava in
the United States, so far as ascertained, three recognized species of


*


FIG. 18.-Anopheles punctipennis: Female, with male antenna at
right, and wing tip showing venation at left-enlarged (original).
this genus. A. quadrinaculatus has just been figured in all its stages,
and the accompanying illustration (fig. 18) shows very well the beautiful




.. L........,ii. % im g ih,;;iiii
HH

44 .....

species known as A. punctipmnnis Say. A. Mnimw (1g.9)
be rarer than the other two and has been taken only in a






.. ,. ii 'i i
......' .



HE









W..










HE *.:J
: : ........... .


....................... .. ..... .E








A .AN. . .... ...
WH'
.... + ::#.. ..........



















1.19.-A vwpekeiea eniana: Female-enlarged (original).

DISTRIBUTION OF THE SPECIES OF ANOPHELES IN THE UNI STEWIATfL
...... ............

















ANOPHELES CRUCIANS Wied.
Habitat: District of Columbia, April 27 (Pergande); Georgia (Nat. MO.); 5 ,SM.
Orleans, La., June 28 (Veazie), November (Thayer); Richmond, V&. (S0oma)Y
ANOPHELE. PUNCTIPENNIS Say.I
(Considered by Wiedeinann to be the same species as his Anophelesia.., bmwenet
the two are certainly distinct.)
Habitat: Castleton, Vt., February 1 (temperature 60 F.); Beverly, Mis., Sp
tember 19, October 2; Cambridge, Mass., June 16, September 30, October 1
(Nat. Mus.); Charlton eights, Md., March 31, November 17 (Pratt); DWte:i::t
of Columbia, June 6 and 7, October 15,25, and 31 (Pergande); Philadelphia, P06,
October 12 (Johnwon); Ithaca, N. Y., April 17, August28 (Comatock); lUsim 3
October 16 (Nrhn); Texas (Nat. Mus.); Mesilla,.N..Mex. (Cockereil); N
land, Jaaiciala (.111 hnson); Middletown, Conn. (Davis); Summit, N. 3., AlHS';
(Howard); Roanoke,.Va., October (Thayer); St.Elmo,,Va., May,"Junelj
Brazos River, Tex. (Woldert); Baltimore (Thayer and Lapear); Walbnu%
... ........ ....
Md. (Thayer and Lazear); Onaga, Kan. (Crevecoeur).. .....
ANOPIHLES QUADRIMACU LAT.S .Say. HI
Habitat: Berlin Falls, N. H., August (Nat. Mum.); Ithaca, N. Y., January. .....
31, November 28 (Comstock); Lakeland, Md., Auguut8; Charlton HeigtMdg
". "H . .







45


November 24 (Pratt); District of Columbia, July, October 15, November 2 and
14 (Pergande); Illinois, September 10, O()tobtlr 10 (Nason); St. Anthony Park,
Minn., December 11 (Lugger); Tick Island, Fla., May 12 (Johnson); Texas
(Nat. Mus.); Oneco, Fla., May 26 (Glossanrd); Roanoke, Va., Octolber (Thayer);
Newport News, Va., October (Thayer); St. Elimno, Va., April, May, June, July
(Pratt); New Orleans (Thayer); Sparrows Point, Md., and vicinity (Thayer
and Lazear); Middletown, Conn. (Davis).


THE GENUS PSOROPHORA.


But one species, P. eiliata, of the genus Psorophora is known in
the United States. This is well illustrated in the accompanying
figure (hg. 20). Although this insect, as indicated in the synoptic


FIG. 20.-Psorophora ciliata: Female-enlarged (original).


tables, is really yellowish in color, yet* the general effect when one
glances at it, or sees it flying, is that it is very dark, almost black.
The wings are not really spotted or infuscated, but the very numerous
dark scales on the main veins make the wings appear dark. They are
also when seen in certain lights prismatic in color effect. The palpi
of the female are nearly half as long as the beak, and the beak itself


Ifc :.,..:..,!:: .. .. .. ...






4 6.. ..:. ::. ..i~l!di..-

is very stout. The most striking feature of this insect,
the curious series of erect close-set hairs or scales on thel
distinguishes it at once from other mosquitoes. This
widespread in the United States, and we have specimens from-
ter, Mass. (Nat. Mus.); Washington, D. C. (Chittenden); WO
N. J., July 2 (Johnson); Illinois (Nason); Brooklyn Bridge, Yw;
23 (Garman); Lincoln, Nebr., July and August (Bruner); Los A4I
Cal. (Coquillett); San Diego, Tex., May 15 (Schwarz); Florid,*"I
(Nat. Mus.); Hastings, Fla., July (Dept. Agric.); NewOR
August, (Veazie). A rather large series was captured in Jmune,,
........................ .iii!i:.............


























Fie. 21.-Megarhinus ridtO.: Female-enlarged (original).
present year at St. Elmo, Va., by Mr. Pratt. The writer felt .certain:
that he would be able to follow out the life history of this species from
the living material captured by Mr. Pratt. Females were placed alive:
in breeding jars under conditions which had repeatedly been successfRi
with Culex and Anopheles, but no eggs were obtained. The breeding:
habits, therefore, may be different from those of the other twogeaiil
and the biology of this form is an interesting and important point tar
future investigation. As elsewhere stated, the possible nhUlij2
between Psorophora and the Hsematamoebwe deserve early in-vestn_
'F T .* ... ..; .. ^*^ 'iginiiiiilffl ^ ^


.... ... ...... :..........: ..::.........: !.






47


THE GENUS MEGARHINUS.


This is the other genus (fig. 21), the species of which are more or
less abundant in the South, which should be investigated by Southern
observers in regard to its possible connection with malaria. As indi-
cated in the synoptic table, the mosquitoes of this genus are readily
distinguished by the curved beak, which is also well shown in the draw-
ing:. They are especially distinguished also by their metallic greenish
or bluish coloration. Nothing is known of the life history of the mos-
quitoes of this genus, and the species known to occur in this country
are distributed as follows, so far as our records go:
MEGARHINUS FEROX Wied.
Habitat: District of Colombia, August 22 (Pergande); (Georgia according to
Walker's list).
MBGARHINUS HEMORRHOIDALIS Fabr.
Habitat: (Cayenne and Cuba according to Osten Sacken's catalogue).
MBGARHINUS PORTORICENSIS Roeder.
Habitat: Benoit, Miss., July 18 (Hine).
MEGARHINUS RUTILUS Coq.
Habitat: North Carolina; Georgiana, Fla. (Nat. Mus.).


FIG. 22.-Aedes sapphirinus: Female-enlarged originall.


THE GENUS AEDES.
The mosquitoes of this genus (fig. 22) are minute forms, insignificant
in color, and the only one of which we possess specimens, viz., A. sap-
phiriust, is shown in the accompanying figure. We have received it




....~~.. ...........: :..
48"

only from Ithaca, N. Y., through the kindness of Pt'. JA:
stock. Another species, A. fuJww, i said by OtOm Sac. I
HA....-ii ;ib
at Cambridge, Mass.
THE NATURAL ENZEMIES OF MOSQUITO&
The late Dr. Robert H. Lamborn, of New York and Phi
while engaged a number of years ago in building the Loke
and Mississippi Railroad, fell in with a great many m .....
often, with a sentiment of gratitude," as he expresed:4 Its
through his mosquito veil at the dragon flies which ...& '
open siaces among the pine trees. "They darted frow- sidii
like swallows in a meadow, but with amazing rapidity, and.,:`
: ... .. .... ..: .. : ::E........ ::
turn a mosquito 'ceased from troubling."' ThiF gave Dr. irm,
the id(lea that perhaps dragon flies might be domesticated 'ad
to destroy mosquitoes along the New Jersey coast and elasewKi;.S.7mH
so he offered prizes for the three best essays regarding U0..hO..d..
destroying the mosquito and the house fly, especially deg ltf ,,^
dragon fly for careful investigation. The successful esmys-by ) ii!f4
C. B. Aaron, Mr. A. C. Weeks, and Mr. William Beutenmfilllr-w s4
published by Dr. Lamborn in a volume entitled "Dragon-The ai:
Mosquitoes. The Lamborn prize essays." The essays were all 40e1r:f'i
lent. Here, however, they are mentioned, by the way, in conneotiom
with the group of the best-known natural enemies of mosquioe%
namely, the dragon flies. It is needless to say that none of tie .ssii
were able to solve the problem of a practical breeding, on a iiiiI
scale, of dragon flies for mosquito extermination, and, inmfat, Us',.
whole subject of the natural enemies of the mosquito is of .ie,.,.
practical importance. It is simply a matter of general i.t......'.l
Dragon flies, as adults, feed upon adult mosquitoes, just as they Wi."-::
upon all other insects which they are able to capture and devour,.
Dragon flies, as larvae, feed upon the larva? and pupse of mo"su i:to,!|
although other and larger and less active aquatic insects and ai iti':
form the bulk of their food. .,
The extreme activity of both larvae and pupae of mosquito es ::::::::!ll
necessary factor in their struggle for existence, since stagnant podi :,
of water fairly swarm with predatory animal life. The larva of ons.:::!l
of the water beetles of the family Hydrophilidae eats hundrek C.'li
other insects in the course of its existence, and the larv of mosqul*itioe
do not escape entirely, although by their extreme activity they doiti.L
a better chance than do other more sluggish species. A small poot
water on the Department grounds at Washington is situated w4....
manure pile, and the water is colored dark brown by the
from the manure. The pool is kept by Mr. Saunders, the iiei.|
tendent of the grounds, for the purpose of securing aure'............
for some of his plants. It is, at all times through the ..
... ".. .. ......' ......., ,... ,,,,i


. ... ..... -... ....:.: :: ::"..: ::"i..





2 '4
49

swarming with the larva of (cdew punyqen, C. stimlntsm and C( per-
Stwrbans; also with the larva of an Ephydrid--Brachydeutera argentata
Walk.-and with the larva of an Ephemerid of the genus Caenis, and
other aquatic species. A number of specimens of Hydrophilid larvae
were found by the writer in this pool. They fed upon the other
aquatic insects with avidity, and three of them were placed in a large
battery jar with about a half gallon of this water, teeming with insect
life nd containing apparently some hundreds of the mosquito larvae
and many of the others just mentioned. These three Hydrophilid
larvae, in the course of a week, practically devoured all of the other
animal life in the jar. Only two male mosquitoes and one female suc-
ceeded in reaching the adult stage.
No one can realize the intensity of the struggle for existence which
R is going on in a stagnant pool until he forces himself to the seemingly
rather unpleasant occupation of lying down by its side and watching
with a large hand lens the various forms of life with which the water
is swarming. Aside from the larvae of the dragon flies and the preda-
tory larvae of the three great families of aquatic beetles, namely, the
Dytiscidae, the Hydrophilid.e, and the Gyrinidae, there are aquatic
neuropteroid insects which are predatory and which feed upon
mosquito larvae as well as others, like those of the genus Hydro-
psyche; and there are aquatic Heteroptera which are also predatory.
Aside from insects, there are many other natural enemies of mosqui-
toes. Many fish eat their larvae and pupae, and such night-flying birds
as nighthawks and whip-poor-wills, and bats as well, destroy the adults.
Harvey (American Naturalist, 1880, p. 896), quoted by Mrs. Aaron,
found 600 mosquitoes in the crop of a nighthawk.

REMEDIES AGAINST MOSQUITOES.
Remedies in houses and the prevention of bites.-Of the remedies in
use in houses the burning of pyrethrum powder and the catching of
mosquitoes on the walls in kerosene cups are probably the best, next
to a thorough screening and mosquito bars about the bed. In burning
pyrethrum powder it is well to moisten the powder sufficiently with
water so that it can be molded roughly into little cones about the size
of a chocolate drop. These cones are placed on a pan and dried in
the oven. If ignited at the apex the cones smolder slowly, giving off
an odor not unlike that of the prepared punk which boys in this
country use to light firecrackers. Two or three of these cones burned
in a room in the evening will give relief by stupefying the mosquitoes.
This smoke appears to be perfectly innocuous to human beings. The
writer has breathed it evening after evening without the slightest per-
ceptible ill effect. The method of catching mosquitoes on the walls
with kerosene in cups is now in frequent use in different parts of the
3949--4


, *,t






50


country. No one seems to know who invented it, but the wrier
saw it in operation some years ago in New Jersey, and was rewte
its simplicity and efficacy. The top of a tin baking-powder&ba. ..Nbl
inverted and nailed to the end of a stick of sufficient length to:
to the ceiling. A small quantity of kerosene is put into this .o.
vised cup and the apparatus is pushed up under resting ."oq... bj..,J
which fall into the kerosene and are destroyed. It is the eon :tpq
certain houses to systematically hunt for mosquitoes in the bui .
with such an apparatus every night before retiring. .
Camphor rubbed on the face and hands or a few drops upon l .iiiiil.
pillow at night will keep mosquitoes away for a time, and thiUs -A ::i::!!!!!!';
a well-known property of oil of pennyroyal. The use of oil of peppwlK
mint, lemon juice, and vinegar have all been recommended as .1.iy,,.
teetors against mosquitoes, while oil of tar as used against the black :::
fly in Canada is also used in bad mosquito localities. Strongly McaM
phorated vaseline, although recommended, has been found by Drn
Nuttall to be of scarcely any use in Canada.
One of the London papers, the Daily Telegraph, invited its readelbr.
to send in mosquito remedies of this kind during the summer of 1899,
and some of the substances recommended were as follows:
Eucalyptol on the skin, with a handkerchief saturated with it placed on the pillow
at night-the result of South African experience. (Arthur E. Edwards.)
Carbolated va.seline. (Dr. George Mackern.) A
One drop of oil of lavender on pillow, and one on the head at night (A. E 8.)
Tincture of Ledum pali.trnR. (M. Fisher.)
Piece of cotton wool soaked in oil of cloves on each side of the bed curtains.
(W B .) .........
Anoint skin with 3 parts refined paraffin and 1 part crushed camphor. (W. T.
Catleugh.)
To heal the bites, a drop of liquid ammonia. (P. G. L) )
Eucalyptus oil. (X.)
Same substance. (Dr. George Cohen.)
Oil of eucalyptus and creosote, each 5 drops, to be thoroughly mixed with I omaen
of glycerin. (R. R. P. S. Bowker.) .
Place a fine, juicy, uncooked beefsteak near the bed on retiring. (M. M. M.) j
A substance with which the writer is not familiar, but which is
spoken of very highly in the interesting paper by the Italians Ce i; iA.
and Casagrandi in a paper to which we shall have occasion to refer I
later in speaking of remedies against the larva, is a yellow aniline color, |
referred to in the work of the Italians as Larycith III. They stats
that a little of this substance burned will kill the adult mosquitoes,
and that this method constitutes the most efficacious means of destroy-,
ing them. The Chinese use pine or juniper sawdust, mixed with a|
small quantity of brimstone and 1 ounce of arsenic, run into slender:[..]
bags in a dry state. Each bag is coiled like a snake, and tied with,
thread. The outer end is lighted. Two coils are said to be sufloiia
for an ordinary room, and 100 coils sell for 6 cents.








Renzedies for ltes.-Dr. E. 0. Peck, of Morristown, N. J., wrote
to this office last summer stating that he had found glycerin ia sover-
eign cure for the bites. Touch the bite with glycerin, and in a few
minutes the pain is gone. According to D)r. Peck it also took the
pain from bee stings. Dr. Charles A. Nash, of New York City, has
recently informed the writer, by correspondence, that whenever a
mosquito bites himn he rubs the spot and marks it with a lump of
indigo. This, he says, instantaneouslyy renders the bite absolutely
of no account," whether the application is made immediately, the next
day, or the day after. He has used it since 1878, and lives in a New
Jersey town where, he writes, "'mosquitoes are a pest every year."
He finds the same application to give relief from the stings of the
yellow jacket. Household ammonia has been found by many persons
to give relief.
DESTRUCTION OF LARVE AND ABOLITION OF BREEDING PLACES.
The following paragraphs are quoted from the writer's article in
Bulletin No. 4:
"Altogether the most satisfactory ways of fighting mosquitoes are
those which result in the destruction of the larvae or the abolition of
their breeding places. In not every locality are these measures feasi-
ble, but in many places there is absolutely no necessity for the
mosquito annoyance. The three main preventive measures arc the
draining of breeding places, the introduction of small fish into fishless
breeding places, and the treatment of such pools with kerosene.
These are three alternatives, any one of which will be efficacious, and
any one of which may be used where there are reasons against the
trial of the others.
"Kerosene on breeding pools.-In 1892 the writer published the first
account of extensive out-of-doors experiments to determine the actual
effect upon the mosquitoes of a thin layer of kerosene upon the sur-
face of water in breeding pools and the relative amount to be used.
He showed the quantity of kerosene necessary for a given water sur-
face, and demonstrated further that not only are the larvae and pupa?
thereby destroyed almost immediately, but that the female mosquitoes
are not deterred from attempting to oviposit upon the surface of the
water, and that they are thus destroyed in large numbers bffiore their
eggs are laid. He also showed approximately the length of time for
which one such treatment would remain operative. No originality
was claimed for the suggestion, but only for the more or less exact
experimentation. The writer, himself, as early as 1867, had found
that kerosene would kill mosquito larvae, and the same knowledge was
probably put in practice, although without publicity, in other parts of
the country. In fact, Mr. H. E. Weed states (Insect Life, Vol. VII,




i .. ......ii::** ii : : ,!! i:ii= : i :. ...... ..........i!ii !,ii

.... ... !'i E :

p. 212) that in the French quarter of New Orleans it has been
mon practice for many years to place kerosene in the water
lessen the numilers of mosquitoes in a given locality, although he:
nothing that had Ibeen written to show that such was the case,
says: In this age of advancement we can no longer go by he
dence.' Suggestions as to the use of kerosene, and even experis:W4
a water surface 10 inches square, showing that the larva could e:::
by kerosene, were recorded by Mrs. C. B. Aaron in her. ,
prize e.ssay and published in the work entitled 'Dragon Flies
. .. .. .. .... .. i ii ii
Mosquitoes' (D. Appleton & Co., 189)). Mr. W. Beuteamxllerli>|
in the same work, made the same suggestion. *
The quantity of kerosene to be practically used, as shown by 'b:,
writer's experiments, is approximately 1 ounce to 15 square i.fOeeti
water surface, and ordinarily the application need not be renewedIf ..i!.!!...
one month. Since 1892 several demonstrations, on both a largeo.. and j....
small scale, have been made. Two localities were rid of the mon qito
plague under the supervision of the writer by the use of kerusm.e .
alone. Mr. Weed, in the article above mentioned, states that he 6 ie
the college campus of the Mississippi Agricultural College of sIO-
(quitoes by the treatment with kerosene of eleven large water tanks.
Dr. John B. Smith has recorded, though without details, success *iI
this remedy in two cases on Long Island (Insect Life, Vol. VI, p. 91).
Prof. .1. If. Comstock tells the writer that a similar series of exlped-
ments. with perfectly satisfactory results, was carried out by Mr. Ver-
non 1-. Kellogg on the campus of Stanford University, at Palo Alto,
Cal. In this case post holes filled with surface water were treated,
with the result that the mosquito plague was almost immediately ......
alleviated.
"Additional experiments on a somewhat larger scale have been mad..
by Rev. John D. Long at Oak Island Beach, Long Island Sound, mand
by Mr. W. R. Hopson, near Bridgeport, Conn., also on the shores of:.
Long Island Sound, the experiments in both cases indicating the eEffi :
cacy of the remedy when applied intelligently. I have not been able .
to learn the details of Mr. Hopson's operations, but am told that they .
included extensive draining as well as the use of kerosene.
"It is not, however, the great sea marshes along the coast, where,
mosquitoes breed in countless numbers, which we can expectto treat
by this mniethod, but the inland places, where the mosquito supply iJA
derived from comparatively small swamps and circumscribed pools,':.i.
In most localities people endure the torment or direct their remed..::ies
against the adult insect only, without the slightest attempt to invest. ,
gate the source of the supply, when the very first step should be the 1
undertaking of such an investigation. In 'Gleanings in Bee o Cu.ur:'
(Ortober 1, 1895) we notice the statement in the Californisa colm.
that in some California towns the pit or vault behind water-clskets|






53


subject to flushing with water during the irrigation of the hiand near by.
A period of several weeks elapses before more water is turned in, and
in the meantime the water becomes stagnant and the breeding place of
millions of mosquitoes. Then, as the correspondent says, 'people go
around wondering where all the mosquitoes come from, put up screens,
burn buhach, and make a great fuss.' Nothing could be easier than to
pour an ounce of kerosene into each of these pits, and all danger from
mosquitoes will have passed.
"In many houses in Baltimore, Md., the sewage drains first into
wells or sinks in the back yard, and thence in some cases into sewers,
and in other cases is pumped out periodically. These wells invariably
have open privies built over them, and the mosquitoes, which breed in
the stagnant contents of the sinks, have free egress into the open air
back of the houses. Hence parts of Baltimore much farther removed
from either running or stagnant water than certain parts of Washing-
ton, where no mosquitoes are found, are terribly mosquito ridden, and
Sleep without mosquito bars is, from May to December, almost impos-
sible. Specimens of Culex rpungens captured November 5 in such a
privy as described have been brought to the writer from Baltimore by
one of his assistants,. Mr. R. M. Reese.
"Kerosene has been tried by Mr. Reese in one case in Baltimore,
and two treatments of a privy made about May 1 and June 1, respec-
tively, seemed to diminish the numbers of the pest in that particular
house; but without concerted action of all the householders in a given
block (all the houses, be it remembered, being exactly alike in the
method of sewage disposal) no great amount of good could be accom-
plished. With such concerted action, however, there seems to be no
reason why the mosquito plague could not be greatly diminished in
many, if not most, parts of Baltimore at a very small expense. Usually
one well serves two houses, the privies being built in pairs, so that one
treatment would suffice for two dwellings.
On ponds of any size the quickest and most perfect method of form-
ing a film of kerosene will be to spray the oil over the surface of the
water.
"Drainage.-The remedy which depends upon draining breeding
places needs no extended discussion. Naturally the draining off of the
water of pools will prevent mosquitoes from breeding there, and the
possibility of such draining and the means by which it may be done will
vary with each individual case. The writer is informed that an elabo-
r rate bit of work which has been done at Virginia Beach bears on this
* method. Behind the hotels at this place, the hotels themselves front-
ing upon the beach, was a large fresh-water lake, which, with its
adjoining swamps, was a source of mosquito supply, and it was further
Feared that it made the neighborhood malarious. Two canals were cut
From the lake to the ocean, and by means of machinery the water of the








lake was changed from a body of fresh to a body of salt water. .
that is somewhat brackish will support mosquitoes, but water
is purely salt will destroy them. -I ....
"Practical tne offtsA.-The introduction of fish intofishless b .
places is another matter. It may be undesirable to treat
breeding places with kerosene, as, for instance, water which is lid
for drinking, although this has been done without harm in'W
where, as is etistoimiary, the drinking supply is drawn from the b;,
of the tank. An interesting case noted in Insect Life (V .
p. 223), in which a pair of carp was placed in each of several ..:
in the Riviera, is a case in point. The value of most small ks m
the purpose of destroying mosquito larve was well indicated by .
experience described to us by Mr. C. H. Russell, of Bridgeport, C o elamHmai.m
In this case a very high tide broke away a dike and flooded the It'.:l......
.. . .... " =. ,!
meadows of Stratford, a small town a few miles from Bridrpo*
The receding tide left two small lakes, nearly side by side and of S ...ii.....
same size. In one lake the tide left a dozen or more small is,:::i:
while the other was fishless. An examination by Mr. Ruaell ain ',i
summer of 18111 showed that while the fishless lake contained tas of. d .....i.
thousands of mosquito larvae, that containing the fish had no larva. .. '....
"The use of carp for this purpose has been mentioned in the preceding *"
paragraph, but most small fish will answer as well. The writer knows
of none that will be better than either of the common little stickle-:.,
backs (Ga.termstus aeuteatus or Pygosteua pungititus). They are sia i,
but very active and very voracious. Mr. F. W. Urich, of Trinid, .
has written us that there is a little cyprinoid common in that is.ad
which answers admirably for this purpose. This fish has not beeu
specifically determined, but we hope to make an effort to introdume It.. .
into our Southern States, if it proves to be new to our fauna. At B 'Bsr&.
ville, Tex., a little fish is used for this purpose, which is there callBed.
perch, although we have not been able to find out just what the speie.
.... ... -.- ,. :+: i"'
is. They" soon eat tip the mosquito larvae, however, and in order t'_o
keep them alive the people adopt an ingenious flytrap, which they keep '
in their houses and in which about a quart of flies a day is eaught ;.
These flies are then fed to the fish. This makes a little circle which
strikes us as particularly ingenious and pleasant. The flytraps c :atch
the flies and rid the house of that pest. The flies are fed to the fGa in
the water tanks and keep them alive in order that they may feed oB?. '|.
the mosquito larvae, thus keeping the houses free of mosquitoes.
"4Artjie;al agitation aif tle water.-Where kerosene is consider. .j
objelctionable, and where fish can not be readily obtained, there tig
another course left open. It is the constant artificial agitation of th.ii:
water,' since mosquitoes will oviposit only in still water. .At.
Iiego, Tex., in the summer there are no streams for many miles,
plenty of mosquitoes breed in the water tanks. Some enterprise






55

individuals kept their tanks free by putting in a little wheel, which is
turned by the windmill, and keeps the water almost constantly
agitated."
Later uste of kerosene.-Since the publication of the recommendations
just quoted, a great deal'of experimental work has been carried on in
different parts of the country, both on a small scale and on large
scales. An unfortunate editorial note published in the American
Naturalist in 1895 states that the writer discovered the kerosene treat-
ment against mosquito larvae, whereas in his first article on the sub-
ject (Insect Life, Vol. V, pp. 12 to 14) he began with the words: "One
of the most reasonable of the recommendations which have been made
from time to time * is the application of kerosene to restricted
and fishless breeding ponds." The note in the Naturalist was the text,
however, for a sarcastic note in the Revue Scientifique, 1895, Volume
IV, page 729, by a writer named Delbteuf, aimed not only against the
writer, but against Americans in general. He stated that he had used
kerosene as a remedy for fully fifty years, and that its use is referred
to in the Journal Pittoresque for 1847, page 80, where it is spoken of
as something already well known. Since the writer made no claims
to any originality, but simply announced exact experimentation upon
a somewhat large scale, the matter may rest very comfortably where
it is. But it is interesting to note here that as long ago as 1812, in a
work published in London under the title "Omniana or Hore Otio- 1
' siores," a collection of odds and ends of all kinds, the following sugges-
tion is made:
The mosquito, which is of all the race of flies the most noxious, breeds in the
water. Might it not be possible at the seasons when they emerge and when they
deposit their eggs upon the surface to diminish their numbers by pouring oil upon
great standing water and large rivers in those places which are most infested by
them?
The writer is indebted to Mr. D. C. Clark, of Baltimore, for this
interesting reference.
During the past few years kerosene has been rather extensively used
at many places in an effort to limit the mosquito supply. As already
pointed out, there are many places where the source of mosquito sup-
ply is definitely limited and easy of treatment, and in such cases on
account of the cheapness of kerosene it will be the best means of erad-
ication. In other places where communities are surrounded with
swamp land or in the case of extensive sea marshes kerosene can be
practically used in connection with other and more elaborate measures,
comprehending, as a rule, dyking and draining. At a relatively slight
expense, however, a country club on Staten Island has during one sea-
son practically stopped the breeding of Gulex piungens in ponds and
marshes in the vicinity by the use of kerosene alone. This substance
has also been used with good effect by the Town Improvement Society



0




..... .." "..d. ..ii::i:d ......i!i~i: :'.:ii "i' ::ii: :i i
EiE .. : ~~.. .. :E ." : ...: . ..: ::.. :E:i.. ":ii.' : ...
...... : . .. :: .: ..... .:...... ... .. .. .: :.i iil
.". .."6
.. .... ....... . .. ... :. .diiiii i
... " !!!"'... .. ... ..

at Summit, N. J., in woodland pools and swmn p land, and itbm.
large scale is be i ng attempted the present year in tile vicinity of
town on Long Island. Dr. A. D. Hopkins, of Moratown, W
.. d ...... ...... ...
tells the writer that about ten years ago an. extensive pumping
was located near the river bank where the oil pipe line crosmae a
above Morgantown and that the oil frequently escpe out syW
*: river. Since that time the city has been almost
mosquitoes.
In 1897, Mr. M. J. Wightman, while interested in devel*pi
resort known as Midland Beach, had 4 barrels of crude:p:.
scattered over the marshes surrounding the beach. For thr: r.
previously the mosquitoes had been unbearable. The
the beach went about with their heads covered with netn,:sS ..
course this had a very discouraging influence upon visitos:.4 iJ
oiled district covered a radius of half a mile, and Mr. Wightms,:w liii*
~~~~~~ ~~.... .... : .di : :i!J !i:ii''
ing in 1899, stated that within three days after the oil was d isr bu..
mosquitoes were rare along the beach. This condition lasted tl',iarouh7=
out the season. Recently, owing to a change of t: ;!!!!!!!1
..... s....
writer is informed that nothing has been done and that moeqalt ..I
have become plentiful again. ,,..-.....i.i...!.
Dr. St. George Gray, of St. Lucia, British West Indies, writes, a ..i.i .
reading Bulletin 4 of this office, that he has tried kerosene in his weD:..::. ,.: .
and in the water jars in his yard with the result that one species .ha
disappeared from his house and that the other mosquitoes give .himi ....i:|.
:: .. ..: ..! i~ ..:.:::
very little trouble. a m r
The remedial experiments against mosquito larvae tried by Thxtafl H
Stephens and Christopher at Sierra Leone are given in the repo aii:iii:ll
the malaria committee of the Royal Society, London, July 0, f1 i. ..i....
They selected as the most practical larvicides kerosene (paraftfn @1'9 !i
and salt. The salt, requiring a very strong solution, was not eoxpui.r.i!!- ..
mented with extensively. A few handfuls thrown into pools coa iilis i
ing not more than 3 or 4 pints of water produced no effect in tin!esiB 1
days. With kerosene the rock pools and small runnells of wat lew .
treated: "The larvicidal effect in the pools was very striking, 4it:o l i
the larva being killed in fifteen minutes or less. In many cases ain.:..
besides the larvicidal effect, adult females were found next day killedi:.!
by the paraffin on the surface of the pool where they had cometo.".i... ^1.
their eggs." Thus the writer's 1893 observation on the non-deterrea:j
effect of the kerosene film on adult mosquitoes and their resulitant|
destruction before the eggs are laid is confirmed. This has ab| s..
...::" ...l ....... ii
seemed to be a point of great practical value in the use of ke ....p.es*.
The final result by the English observers, however, was found to tb 4"
immediate return of the insects on the cessation of the appliak,
petroleum. An interesting test experiment was made by them u ....p....
surface drain arising from a spring and running for 300 yards .. w.h.






57

entered a brook. The spring was free from larva, but the drain teemed
with them throughout its entire length. Over this drain kerosene oil
Swas sprinkled by means of a watering pot. About 4 gallons sufficed to
cover the drain thickly with oil. "The larvicidal effect was imme-
Sdiate, and on the following day no living larval were seen. Four days
Slater traces of oil were still present in places. Eight days later small
larvme were present along the whole drain. A weekly appli-
Scation of paraffin then would effectually prevent the formation of the
Perfect insect in these situations."
S The rapid disappearance of the kerosene covering in this last experi-
Sment is quite contrary to the results of our applications made to still
pools of water. This may have been due in part to the fact that there
was more or less of a current in the drain, and may also have been
due to the use of an especially volatile kerosene. The writer is now
Advising the use of the grade known as lubricating oil as the result of
the extensive experiments made on Staten Island. It is much more
persistent than the ordinary illuminating oils. i
An interesting plan, suggested to the writer by Mr. W. C. Kerr,
of New York, in conversation, to disseminate oil over salt marshes,
was that of putting barrels of oil in the marshes in winter when the
ground is frozen and piercing the barrels with small holes so that the
oil will escape slowly through the following breeding season. The best
method of distributing oil on the surface of water is a practical ques- .
tion which each experimenter is apt to settle for himself. The writer
has adopted the plan of simply pouring the requisite quantity of oil
upon the water and allowing it to spread by itself, which it does in the
course of time. The Staten Island and Summit, N. J., people use a
spray pump, but in some ways this seems to the writer not perfectly
satisfactory. A great deal of kerosene is apt to be wasted and the I
continuous layer of oil which is desirable is frequently not brought ,
about. The Liverpool School of Tropical Diseases advises as the
result of the Sierra Leone work that the oil can b)e best applied by I
Smearing the pool with a rag fixed to the end of a .stick and dipped in
a pot of oil. "In this manner a number of pools can be dealt with in
five minutes at the expense of very little oil."
OTHER LARVICIDES.

Permnanganate of potash.-Other substances have been experimented
with. Two years ago many newspapers contained an item concerning
the use of permanganate of potash. As this item was credited to the
Public Health Journal it gained a great deal of credence, and was
afterwards mentioned in an interesting article by Mr. A. C. Weeks,
in the Scientific American. The published note read as follows:
Two and one-half hours are required for a mosquito to develop from its first stage,
a speck resembling cholera bacteria, to its active and venomous maturity. The


=--j






58


insect in all its phase may be instantly killed by contact with minute q
pennanganate of iotahdi. It is claimed that I part of this sulmaitance in ..
solution distributed in mosquito marshes will render the development of
imuinjwible; that a handful of permanganate will oxidize a 10-acre mwapp,
embryo insects, auiI keep it free from organic matter for thirty days, at a coat:i !
centi; that with care a whole State may be kept free of insect ipest at a Mi
An eftlchutim methodi is to scatter a few crystals widely apart. A sipgle #" o
permnianganate has killed all the germns in a 1,0001gallon tank.
The item is so obviously ridiculous upon its face that it would la-- y '..
seemin worth while to make any attempt to refute its statements*.S. r i1:!!,
ertheless, it has been so widely read that definite experiimmtolu:,iiii,
seems necessary to set the matter at rest. The unknown t. i ,'i"I Yn ^
ignorance of the life history of mosquitoes in the opening sWm isw^lll '
need not necessarily imply that he would not know a good remyedqi:
he found one. Careful experiments were undertaken by the writer 9%,)i^
in July, 1898, with various strengths of permanganate of potah b i:.....
water containing mosquito larvme from one to six days old. It w i:i::
found that small amounts of the chemical had no effect whateverupou ..
the larvae, which were, however, killed by using amounts so large that, i
instead of using a "handful to a 10-acre swamp," at least a wagon.:
load would have to be used to accomplish any result. Moreover after..
the use of this large amount and after the larvae were killed, the amm ....
water twenty-four hours later, sustained freshly-hatched mosquito
larvte perfectly, so that even were a person to go to the prohibitive
expense of killing mosquito larvw in the swamp with permangast
of potash, the same task would have to be done over again twodaya '
later. .:
The same conclusion was subsequently reached, after careful exper-.:
ment, by Dr. Lederle, of the New York health office, and by the Ital-
ians Celli and Casagrandi. ]
Proprietary mixet,.reA.-A number of proprietary and secret mix- i
tures recommended for mosquito-breeding pools and which have been
put on the market since the wide-spread interest in the mosquito queus....
tion has sprung utip have been tested by the writer, but none have bees *
found more satisfactory than the cheapest petroleum oil.
Fr.perniment8 of Cell! and Casagrandi.-The most extensive series of.
experiments with culicidal mixtures which has been made was con .
ducted by the Italians Celli and Casagrandi, above referred to. They
have tabulated in the "Annali d' Igiene Sperimentale, Rome (Vol. IX,
Fase. Il, 1899, pp. 317-353), the results of experiments with many.;
4ubstances. Referring to petroleum, they say that apart from 't.e:i
question of the expense, which outside of America is worthy of note,.|J
the action of petroleum in destroying mosquito larvw is not always tO.,ii
be put in the front rank. Their conclusions are practically as follow-s.....
(1) Of the whole tperiiod of the cycle of development of nlosquitoes the s.B..i...|
which they are mn(t easily destroyed are those of larvae and of the aerial m ....td||...
and larva. are most easily killed the younger they are. ..







59

(2) To kill the larvaw, among numerous substances experimented with, there will
nave, in decreasing order, culicidal action: (a) Mineral: sulphurous oxide, peruman-
ganate of potash with hydrochloric acid, common salt, potash, ammonia, carburet of
lime, corrosive sublimate, chloride of lime, the bisulphites, sulphate of iron or cop-
per, lime, bichromate of potash, and sodium sulphite. (b) Organic: powdlers (;f the
unexpanded flowers of chrysanthemum, tobacco, petroleum and oils, formahlin,
creso-, certain aniline colors (gallot, green malachite), coal tar. Taking into account,
however, the dose necessary to kill the larvwe, tht practicability and the price, all of
the mineral and some of the organic substances are excluded, and there remain as
available the vegetable powders, petroleum, and the aniline colors.
(3) To kill aerial mosquitoes, we have odors, fumes, or gases. Among the odors
are turpentine, iodoformn, menthol, nutmeg, camphor, garlic. Among the fumes
are tobacco, chrysanthemum powder, fresh leaves of eucalyptus, quassia wood,
pyrethrum powder. Among the gases, sulphuric oxide. It is, however, to be noted
that for these odors, fumes, or gases to exercise their culicidal action they must fill
or saturate the whole ambient; otherwise they produce only apparent death, or at
most only a culicifugal action, which sometimes in houses may be useful in protect-
ing man from being bitten by mosquitoes, and preventing the latter infecting him
when they have sucked the blood of malarious persons.
(4) The problem of the destruction of mosquitoes is experimentally soluble, but
practically it will only be so when economic interests desire it. In this latter sense
it is remarkable that the old larvicidal use of petroleum has not become much diffused
in those places where it is very cheap. The chrysanthemum plants might be grown
on a large scale, this making the malarial place itself produce that substance which
frees it of the mosquitoes that infest it.
(5) The opportune season for killing the larvae is in the winter, when they are in
least numbers in the waters and new generations are not born; this also is the season
for their destruction in houses, for they come here for a warmer abode. Their habits
and places of nesting should be studied to this end. This may not be accomplished
on a large -scale as easily as some boast; nevertheless, after the treasures spent by
nations and individuals for preserving vines and vegetation from the oidium, the
peronospora, and the phylloxera, we may hope that something may be done for
protecting the life of man from the mosquitoes of malaria.
It will be noticed that they really exclude from further consideration
all substances except vegetable powders, petroleum, and the aniline
colors. By vegetable powders they refer to the powders from the
flowers of plants of the genus Pyrethrum, and their experiments up)On
* the aniline colors practically center upon the recommendation of the
substance already referred to as the yellow aniline dye which they call
"Larycith III." This color has the property of other aniline colors in
that it is soluble and diffusible in water. The practice recommended
is to make a concentrated solution, which is poured into the pool or
pond to be treated. It is said by the authors that it will destroy all
insect life and fishes, but is harmless to warm-blooded animals; thus
domestic animals may, without danger, drink from pools being treated.
Just what "Larycith III" will prove to be and whether it will be
available for use in this country unfortunately can not be ascertained
at the present moment. Correspondence has been entered into with
large dye firms in New York who have sent abroad for information.
Dr, Ross, in his article in Nature of March 29, previously referred
r





.......*... i ,, -... -...


IF .. --- -- -7vl




:": .. .... ...... : "" :. :i i# 'ii~ iiii
6 0.... .. . ..
... :. ... :... .
... .........iJi

to, says: "On the whole, the most promising method .whiCh:::
itself is the employment of some cheap solid material or
dissolves slowly, which kills the larva without injuring higher
and which renders small pools uninhabitable for the* larva iLw
months. If, for instance, a cartload of such materi woul i-
to extirpate the larvam over a square mile of a malarious ii .
result would be a large gain to its healthfulness. Dr. Fiei V
has lately reported favorably on tar." ..........
Tar and Ut comnpound..-Again, in the report of the *.
." ..." :"....... :: : :
School of Tropical Diseases the following words occur: "Perh. "i
permanent oil than kerosene would be more permanently e'E.$Sii 't
Fresh tar dropped in a puddle makes a film like that of oil stuiidHit
been favorably reported on. Quicklime has been suggested, :hd :il...5...
these should certainly be tried." ......
The writer is rather at a loss to know exactly what is meant by f:b!::i^
expressions ""fresh tar" and "tar" in the above paragraphs. H ie- ii.l
conducted an experiment, however, with a substance known toi:. O*"-iiii
trade as "coal tar," a thick viscid liquid. A few large drops of' SM.f:IYi::J
substance were dropped into a glass vessel containing appro.ximt..ly
2 quarts. of water in which were more than 100 full-grown larva-utii
Culex. All the drops but one sank at once to the bottom, the l"'t oo |
floating upon the surface for some time. No surface film seemed joI J
form from the tar, but after the expiration of forty-eight hours thiet0
~ ~ ~~~...." :; .. : ..... ::b i''
water was found. to be more or less impregnated by the tar, hsilBg ^^
turned somewhat darker in color, while the odor of the tar was ,iB
ceptible. At the expiration of five days nearly all the Culex Iavia:ii
were dead; 1 had succeeded in transforming to pupa., and 5 or 6 remained
at the surface enfeebled and dying. Thus more than 95 per entity h ..di...
been killed. In the meantime, however, twenty-four hours after. t .......
experiment begun, 3 egg masses were laid on the surface of the i: iil
by outside females of Culex. These had hatched in forty-eight .hioh6HM:i::=::
more, and on the fifth day, although the original full-grown lsrv :;:::,
were practically exterminated, many young larva were swnrmia i..:
actively about in the tar water. They continued to grow and .to1..
remain apparently perfectly active and healthy, although the odor of _5
the tar was distinctly perceptible and the color of the water was dair i
and even a thin oily film remained over a portion of the surface. ::
From this experiment it was plain that the killing effect of theitwr.:::!
in the preparation used is comparatively fugitive, and it was atit.:i:
decided to test some of the coal-tar products. The object of tahisRi.-
of experimentation was not only to test the suggestions of the Iagl5iih
observers, but also on account of the fact that as almost every ni
munity manufactures its own illuminating gas it was oondsidered i
easy and probably econominal way of securing a mosquito lslcIde
it should prove to be effective. Coal tar is distilled into various ....






61

of oil, and two of the heavier of these grades were used in the suc-
ceeding experiments. One of these waLs called "creosote oil," and was
a rather light oil of a specific gravity of 1.035 at 60 F., and the other,
bearing no name, was somewhat heavier. The experiments were nc-
essarily on a somewhat small scale. Eighty nearly full-grown larvae
of Wlex 8ti'.tItulant and C. yelturlban. were placed in 3 quarts of water
and one-fourth ounce of creosote oil was poured in at 4.15 p. m. At
5.45 17 pupae and 3 larvae were left alive. The next morning at 9
o'clock it was found that 8 adults had issued over night, but all had
been killed by the creosote. At 3 p. mi. of the same day, twenty-three
hours after the introduction of the insecticide, all larvae and pupae were
dead. With the slightly heavier oil, 150 larvae of the same species,
all full grown or nearly so, were placed in 2 quarts of water and three-
sixteenths ounce of the oil was added at 4.15 p. in. At 5.45 all were
dead except 28 pupae and about 30 larvae. The next morning at 9
o'clock it was discovered that 10 adults had issued over night, but had
been killed before flight by the oil. At 4.30 p. m. of the same day all
the larvae were dead, but 10 pupae were still active. On the following
Morning, at 9 o'clock, forty-two hours after the application, all larvae
were dead and the adults bad issued from the remaining pupae, but
had been caught by the oily film in the act of issuing and had died
Supon the surface of the water.
Still another experiment was tried with pupae only. Two hundred
and fifty pupae of the same Culices were placed in 3 quarts of water
and-one-fourth ounce of creosote oil was added. Twenty hours later
many of the pupae were still living, but thirty-six hours from the time
of application all were dead, no adults having issued. A check experi-
ment with kerosene was carried on parallel with this last experiment
with creosote, anhd it was noticed that the action of the kerosene upon
the pupae was much quicker, all dying within forty-five minutes. A
few young larvae, however, in the same jar lived for several hours.
An interesting effect of the application of the creosote in the first
two of these experiments was that it seemed without doubt to hasten
the transformation of the insect. When at 4.15 the creosote was
poured in jars 1 and 2, no pupae were observed, but all larvae were
full grown or nearly so. After fifteen minutes 10 pupae were observed
in jar 2 and 5 in jar 1. Ten minutes later 15 were counted in jar 2
and 13 in jar 1. Twenty minutes later there were 19 in jar 2 and 2
in jar 1. Fifteen minutes later still there were 19 in jar 2 and 22 in
jar 1. Thirty minutes later there were 17 in jar 2 (2 having died in
the interval) and 28 in jar 1. As above stated, over night a number
of adults issued, 10 in jar 1 and 8 in jar 2, and twenty-four hours later
10 more adults issued in jar 1. It must be remarked that the full-
grown larvae struggled violently on perceiving the uncomfortable
presence of the creosote, and as they were just ready to transform this



... ..









leaving the pupa bare. This transformation from "larva to .
hardly an interesting as the rapid development of adults, 18o
issued within fifteen hourn after transformation to pupa,
previously the shortest duration of the pupal state which.
observed was forty-eight hours. It looks like an effort of na#'
perpetuate the species in the presence of a unique emergency.
On the whole, the result of the experiments with tar and tar ............
rather unsatisfactory as compared with the heavier grades of k..os..
The effect of the tar was not permanent, and the effect of the f: i
oils w as not as rapid as that of kerosene, and the writers incliu lhi
the opinion that the heavier grades of kerosene oils are, on the w h ::
preferable, although the effect of the creosote oils is very good, d
they can be used to advantage. He is inclined to think that they irny
prove to be more permanent, although not quite so rapid in tef
... :: EE :E . ... ...





effect, than the lighter illuminating oils.m e i

EUCALYPTUS TREES.

In addition to the use of eucalyptus oil on the skin to keep mosquitoes
froi biting, the growth of eucalyptus trees is said by certain person ...........
to drive mosquitoes away, and trees of the genus Eucalyptous hae
been especially recommended for planting in malarial regions. Mr..
Alvah A. Eaton, of California, wrote us in 1893 that in portions of....
California where the blue gum occurs no other remedy need be sought
for. Further than that, he stated that no matter how plentiful the me..
quitoes, a few twigs or leaves laid on the pillow at night would sexam
perfect immunity. The same year Mr. W. A. Sanders, of California,
sent the following interesting account of the value of eucalyptus rees ,
in answer to our published request in Insect Life:
I have the largest and oldest grove of trees of Eucalyptus globtdua in this pt of
California, and have had fifteen years of opportunity to study these trees insw ect
repellants, and deem it my duty to respond to your request on page 268 of e
Life.
Thirty-three years ago I spent a portion of one summer with a Dr. MiConnell, wvho6
had just returned from some years of residence among the uEucalyptus forests of An ...
tralia. We were in the Sequoia (Sequoia sempervirens) forest of the coat region of .
our State. The mosquitoes were so bad that it was nearly impossible to work doing
days when there was no wind. The doctor assured me that our common mosquito
was never found in the Australian Eucalyptus forests and swamps, but added, There's *
a "spotted mosquito" nearly as bad there in some places. He, not being an entomolo
gist, was unable to tell inme whether the "spotted mosquito" was a species of tie
genus Culex, or of some allied genus. . .S..
The doctor wing a reliable, close observer, I determined to test the antdmoest
qualities of the Eucalyptus; so when I began to improve my house here diesn .j
years ago, one of the first things I did was to get a lot of eucalyptus seed from AR l:
tralia and plant out a grove oitees tt the trees. The tallest of them ae now over 140 iset
tall, and can be seen for 20 miles around. My house stands in the midt of tti.'


MEMEMMEMENISM
...... ... .... .
I ........... ......




== I::


"I 63

S trees. My irrigating ditch, a 4i, zt'.l hf.t. wide, otf sluggishi current, runs thr(ughl "tile
Grove beside the house. TIerie lias Iever a single ianiilito) larva 1e.en cmtn ini the
S ditch from where it enters tliltr first sladth (of these trees to when it etierges froim them
200 yards away, while alov at 't 1d l elow nmsluiito larvaie are plentiful-not. immnie-
diately below, hut some hiundmreidls of vards away, where til wathr stands in pools
and becomes stagnant allmong a gr nwth I (if black walnuts and .ott nwods.
My live stock pasture in this tinltamr, going into tilh walnuts and back again under
the eucalyptus shade at pleasure. Frequntly w1 nn thet' cwaWK 0 jwsc up at night they
bring a swarm of uimosquitoeas; ,ccasinally stime (if thlnai get into tihe house, Iut .
cause us so little a:naIi'anc( tlat we scarcely notice thcia. Before this ditch reaches
the Eucalypti it rims through a jungle of "fence bainboo.," (Arund,, uimwropliylla),
where the mosquitoes are so bad that we avoid working there except on the windiest
days. And, though thlie ditch hias more current there, the larvae of mosquitoes are
plentiful in the water till it reaches the Eucalyptus trees, below which 'point none
are found till it has become stagnant away below them.
People who have camped along thle willows of Kings River, only a few miles
away, have come here with faces so blotched and swollen from mosquito bites as to
be hardly recognizable, and have camped in the shade of "Sanders's gumin trees," as
my grove is popularly called, for weeks, and declare that they never even heard a
mosquito sing during that time.
To the non-botanical reader I may say that this species of Eucalyptus is very tender i
to frost. The coldest weather ever known here, 19 F. above zero, killed thousands
of them.
Dr. Nuttall points out that the planting of eucalyptus trees is not a
sovereign remedy, from the fact that malaria still prevails at Tre
Fontane, outside of Rome, in spite of Eucalyptus plantings. The
mere planting of trees, however, is undoubtedly of use in malarial
districts, since it will modify the condition of drainage of the soil.
In view of Mr. Sanders's strong evidence it really appears that plant-
ing of eucalyptus trees will be worth while in certain locations, not
entirely (on account of the conflicting and not thoroughly satisfactory
evidence) for mosquito protection, but incidentally for this use as well
as other purposes.

DRAINAGE AND COMMUNITY WORK.

After all, the best of the means which may be adopted against mos-
quitoes will always consist in the abolition of their breeding places.
Small pools with stagnant water can be treated, but it is a great deal
better to drain them or to fill them up. Swamp areas must sooner or
later be drained. It is perfectly obvious that the sooner this is done
the better from every point of view, not only from that of human
health but from the increased value of real estate in the neighborhood
and from the practical value of the reclaimed land itself. The time is
coming, and rapidly, when this drainage of large swamps will not
remain a matter which concerns the individual owner of the land, but
one for town or county action, and even for States.. The report of
T. J. Gardner on the policy of the State respecting drainage of large
swamps, published in the Report of the Board of Health for New York,





K. .








coveries, is well worth reading by all public-mindd pedol::
annual reports of the State geologist of New Jersey for 1892T al
in which the reclamation of the great Hackensack Meadows,
City, Newark, and Elizabeth, N. J., makes interestingre.d
this line. Work on these marshes has actually been b
solution of this case is taking the form of separate action by .
their municipalities, each improving the territory within its
limits. The city of Newark has a tract of 4,600 acres of .mark
its limits; Jersey City has within its limits 2,086 acres of W..:::
and Elizabeth has 2,658 acres. The three cities, therefore, mbhis
8,700 acres of the 27,000 acres lying between Elizabeth and n
sack. The sanitary importance of reclaiming these lands ldfislf'
greatest, but the capabilities of the improvement plans are ai
attention on the part of capitalists and business men, who see inS i
tide lands valuable sites for manufacturing, industrial, and oomimwil'|i|
.. ... .. 4, ... iii~i
activity.
Even to individual land owners of a community, the drsinqe 4iiii,.
swamps and the consequent abolition of mosquitoes will in many caMses,::,,]
become well worth while. The writer knows of a town in New Jersey,
with a good elevation, within easy distance of New York, and admirably-:-::-:
adapted for summnnier residences of New Yorkers, where the mosquitoesI
are so abundant as to prevent the rise in the price of real estate. A, .l
examination of the surrounding country has convinced him that if the I
large real estate owners were to club together they might, by-thqe..:
expenditure of a few thousand dollars, largely do away with the mw '.i,
quito plague. Another case which is well worth specific mention, sad..,
the truth of which the writer will vouch for, may best be told in the
words of a correspondent, printed in one of the Flushing papers late ','
in March: l
In the town of Stratford, Conn., where I have resided for the past forty-five yeaq ... ::.i.
we have been greatly plagued by swarms of mosquitoes, so great, in fact, that the |
"Stratford mosquito" became a well-known characteristic of Stratford. We has in.
the southern part of our town, bordering on .the sound, several acres of marsh lnd
or meadow, which would become periodically overflowed with water in the sumaf W7
and a tremnienduu4 breeding ground for mosquitoes, and this plague to the town ..1,,M
tinued until about 1890-91, when a party from Bridgeport, Conn., purchased a le ."
section of the meadows and began to protect them by a dike, both on the north adlm4
south ends, which shut out the water. In addition to this, numerous drain ditchh: .
were made, which helped to carry the water away. The result of this work ma :'i
the land perfectly dry and spongy, so that after a rain no pools collected on the m ii.
face of the meadow and prevented the creation of the mosquitoes. The t iaxwie6X:,
tion was so remarkable that people outside the town would hardly believee that Nli
had been effected, and a year or two later the town voted a special approprqi1a1tioilmj'
$2,000 to the party who undertook to build the dike and render the mtsdomIajaIM.
quito proof. It had also the effect of placing on the market a large tract odf i
elevated from the sound for residences, and as many as 25 summer residam1ics






"15

been built upon this land hodwhring tic Nounil, Iandi are increasing each year. They
are free from minosIquitoes, j t hat th" op(ratin it. MlAuiws the economy and their benefit
that will result by using siiIt*' iiit'ans for eliminating the mosquito-breeding pools.
As to community work, we must not fail to mention the interesting
fact that the city of W inchester, Va., is reported to have passed an ordi-
nance requiring property holders to treat drains and stagnant pools of
water with kerosene during the summer season. Winchester is a town
of high elevation and has for a long time enjoyed a reputation among
Virginians as a cool place to spend the summer. Mosquitoes, we are
told, however, made their appearance there'a few years ago, with the
effect that summer visitors became fewer and fewer. The passing of
the city ordinance was deemed a matter of public policy and met with
general approval. Police measures of this kind may not be inadvis-
able under certain circumstances. Surely in such instances as the
Baltimore case, mentioned in previous pages, it seems entirely appro-
priate that the board of health should be called upon to enforce kero-
sene treatment.
3949-5


















L: . .i ....








*4
APPENDIX.
S" '::.:::...."" :iri,.::: i:i|iily i

AN EARLIER ACCOUNT OF THE LARVA OF ANOPHEILS.
Just as this manuscript was about to be sent to the printer Sin
writer's attention was (tailed to a paper by P. Meinert, entitled ,I W:a
encephale Mygelarver" (Sur les larves enc6phales des Diptr; lamai|Qsr^.
mDurs et leurs metamorphoses), K. Danake Videnskaberne Sulwkipiiiiii
Skrifter (Copenhagen), iii, pp. 373-493, Pis. I-IV (1886), in whi .......
among other observations, he gives a brief statement concerning Ano|
pheles which is sufficiently interesting to translate: ^^
. "Anwphel .-ln the 'Observations d'Histoire Naturelle' of J:
one finds a description of this larva, "Description of a new fish, '
which is rather insignificant, anid a drawing which is not badly don a
The larva drawn by Brauer as Anopheles is a larva of Dinx, and thms:. ill
reported by Fischer d'Waldheim as C. claviger are larvae and nymphs :L.
of the genus Corethra, while his nymph is a Tanypus, and his Ey .a
Anopheles. Aside from this, Gerke has briefly mentioned this larva |
in his paper entitled 'On the metamorphoses of the dipterous gen=i,
Dixa,' page 166. 'S
hThe larva of Anopheles lives in still waters or in a weak current ,
with a rich vegetation, in wooded or unwooded regions. It does not
like the shade of great trees, but seeks the sun and the light, as is "i:
indicated by its fresh green color. It does not hibernate, but in mild
seasons it is found in a half-grown condition by the end of March. In
July or a little later in the course of a summer the second generation
of the full-grown larva are found, and in 1882, a year when the spring -
was very forward, the writer found at the end of October small larvae .
which certainly belonged to the third generation; but it was not to be
supposed that these larvae would become full grown, since as they live
at the surface of the water the first film of ice would. kill them.
"The larvae hold themselves at the surface of the water, where they
float with the extremity of the abdomen turned toward the bank or
toward the plants which cover the surface. The larva is stretched out i
in the water with the respiratory tube at the surface. The larger part
of the axbdomen and posterior part of the thorax are submerged, only
a little portion of the prothorax emerging. The head is under water. 3
The long hairs with which the body of the female is provided on the
sides, on the metathorax, and the first three segments of the abdomen :;|
are of great assistance to it in maintaining a fixed position. It rests f
often for a long time immovable and only occasionally changes its A.:i:
location. Its movements denote a certain apathy or indolence, but at; ::
the same time much prudence and apprehension. When it moves
66 i




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67


moves rapidly and dives to the bottom of the water. Recovering from
its fright, it rises obliquely to the surface.
"Just as with the larvae of Culex, the larvae of Anopheles live upon
organic microscopic particles which float upon the water, and which are
brought into the mouth by the movements of the rotatory organs.
These organs are much more developed than with the larvae of Culex,
and while they serve, like the former, as a brush or sieve to strain their
food the larvme of Anopheles, like those of Simulium, holding the head
stretched forward, use them to agitate the water. The larvae of
Anopheles present this peculiarity, that in producing these currents,
which they do the greater part of the day, they lie upon the belly
with the under part of the head turned upward. This rotation of the
head is executed with the greatest rapidity: and scarcely, for example,
have the larvae come to the surface to float, when, by a rotation of the
head upon its longitudinal axis, it is turned bottom side upward and
commences to agitate the surface of the water. This agitation is
undoubtedly for the purpose of drawing floating objects surely and
completely into the orifice of the mouth. This, however, is not neces-
sary, for often one sees the larva with its head working in normal
position, mouth organs below, but in general they do not remain in
this position for a long time, shid it is only after having turned the
head upward that they seem to work con am ore.
"As a rule the larvae seek their nourishment while they are floating
at the surface, but at other times they descend two or three inches
under the water. They can rest several minutes in this position with
the head below, after which they come to the surface again."
This account shows that Meinert knew the larvae very well, and one
can only regret that he did not describe the eggs and the pupae.

THE MALARIAL EXPEDITION OF THE LIVERPOOL SCHOOL OF TROPICAL
MEDICINE.
This interesting and most valuable report was known to the writer
only by brief newspaper notes until the present bulletin had reached
page proof-too late to insert in proper place several important obser-
vations made by Ross, Annett, Austen, and Fielding-Ould. To-day
(August 13) it has reached him in Volume 11 of the Thompson Yates
Laboratory Reports (University Press of Liverpool, 1900), and he is
glad of the opportunity to add the following paragraphs quoted from
its pages:
8. METHODS FOR ASCERTAINING DEFINITIVE HOSTS.
The long researches of one of us in India, followed by those of Koch, Daniels, and
the Italian investigators, have given us a very exact knowledge of the life history of
the Hiemamcebidae in gnats, and have shown us how to detect them in the insects
with ease and certainty. It has been noted that in inhospitable species of gnats the
ingested parasites perish within the stomach cavity, whereas in hospitable species
the zygotes escape from that cavity and develop in the tissues, ultimately giving rise
to blasts which are found in the juices and salivary glands of the insect. * *

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15. BIONOMICSR OP ANOPHEMLE LARVAL
We made the following observations: .
(1) Fgg.--These are boat-shaped, like those of Anophei observed in India. iij
appear to be laid singly on water, but cohere by their ends, forming typical
lar patterns, and also adhere to floating objects, the sides of the veise], etc..W:.,'
observed no facts indicating that they are ever laid on solid surfaces. In io
take about twenty-four hours to hatch, but the period is probably much qh1atr ?ib i
puddles.
(2) Ihural im of lirril age.-This depends on temperature and amount of f
Under natural conditions it may probably be only three or four days, but undo*rab: 'l!*ll
vrable conditions (coll, overcrowding, absence of food) it may (certainly ex.uu.ui:J"|ll
weeks.1 There are reasons for thinking that development i. much haasdse b:.i":
bright weather, in tinirder t, enable the imago to hatch out before desiccation .lO ,:e
containing puddle. :::;
(3) Food.-The larvae were frequently watched floating on the surface and hediny !
on filaments of waterweed, amongst which they often entangle themselves. On 4 iA-b "
section the intestine was found crammed with these filaments. It was observed tA J
in ritro the larvae scarcely grow in size unless they are given large quantities of iwater ]'
weed, which they dispose of very rapidly. On the other band, larva were often
caught in puddles in which no green vegetation could be seen. They may eat oth& '
food, but it would seem as if waterweeds constitute their favorite diet. It wsam 'a-'l
noted that they obtain shelter among these weeds from the current running throqi" ..i
the pools during or after rain. :
(4) Enemies.-No observations could be made under this head, but we often foasd ai
many frogs and tadpoles in the breeding pools, apparently living at peace with the I
larvae. I
(5) Effects of desiccation. -During most of our stay in Freetown heavy showers I. f
several times a day, so that the larvae could live secure from desiccation in all bu t
the most evanescent puddles. In September, however, there was a complete break
in the rains, lasting three days. A large number of the pools, even many of thrmn
containing waterweed, and those fed by springs during rain, dried up completely.
The question whether the larvae had the power of living in the mud at the bottom omt
the pools could now be tested by direct observation. The break in the rains w i
followed by heavy showers, which immediately refilled all the puddles. Had the
larvae continued to exist in the mud, they would now have emerged again. As :
regards the puddles in which the mud had completely dried, this was not the CeM.
No larvae at all were found in them for at least two days after the rain had refilled '"
them. After that interval larvae again appeared, but they were very small os, ..
evidently just hatched from the egg. On the other hand, it was frequently i
observed that if the mud did not become completely dry, the larvae would emerqp .
into active existence after another shower. These observations were supported by .
some experiments in Hiro, and we therefore conclude that the larvae can withstand .
partial, though not complete, desiccation.'
(6) The sante puddles onltmatly o( cupied.-We have suggested (paragraph 13) that
the position of the breeding pools may change according to the seasons, but while we .
were in Freetown there was no change of season, and we generally found Anopkd "
larvae in the same puddle, namely, in those which were suitable for them. Thus, e i
two puddles lying close together, one would never contain larvae and the other
would always contain them. The explanation of this probably is that the larva

One of us kept Cule larvae alive for two months in a bottle in the cold weather :
India. 1.. Ji
One of us reared adults from full-grown larvae kept on damp blotting paper 1b.a:
India), but found that the young larvae died when kept under these condition ..,,
;: a::. 1 :.iii ::ii ii







69

perish in the unsuitable pools, or that the adults generally return to the same pools
in order to lay their eggs. It seems likely that the adult.4 generally lay their eggs in
the pools in which they themselves were bred, and that the insects thus learn by
experience the places most suitable for them.
(7) Detection.-It is easy to overlook Anophelow' larvae unless they are searched for
in a bright light.
(8) Pupae.-The pupae of Anopheles seem to be smaller than those of the cunm-
moner species of Oulex. They require about forty-eight hours to reach maturity in
qiro; perhaps less in natural conditions.
16. BIONOMICS OF ADULT ANOPHELES.
(1) Hatching.-The adults generally hatch out in the evening; but their exit seems
often to depend on the meteorological conditions of the moment, andil appears to be
delayed by rainy and windy weather.
(2) fbod.-They can easily be kept alive in glass cages, test tubes, bottles, etc.
We kept some in this manner for a fortnight, and could doubtless have kept them
longer if we had wished to do so. We are able to confirnn Bancroft's statement (18)
that gnats feed on bananas; but they seem to prefer the fresh fruit. During the day
the insects remained at rest on the walls of the cage, but in the evening began to
fly about and to walk over the fruit, plunging their proboscis into it in many places,
so that the banana was sometimes covered with gnats, both male and female. They,
also drink water frequently, and each can often be seen to be distended with the
fluid. Raw meat was offered to them, but they could not be observed to touch
it. Earth placed at the bottom of the cage seems to be suitable for them.
According to the accounts of the soldiers at Wilberforce, they bite almost entirely
in the evening and night, but have been known to feed on men during the day.
They can certainly be fed on men artificially during the daytime, simply by placing
them in test tubes and then applying the mouth of the tube to the skin. The stom-
ach can be observed to become distended in from one to two minutes or more; after
which the insect continues to suck, but commences to evacuate by the anus serum
containing a small percentage of red corpuscles. Cule. voids only a clear fluid under
the same circumstances. The insects sometimes continue sucking like leeches fur
five or ten minutes, voiding blood all the while; but at other times soon withdraw
the proboscis and then try another spot. It was noted, however, that A11op/h'lts
fed in this manner, even after they had remained sucking for five or ten minutes,
never showed any great distension of the abdomen; while the contents of the stom-
ach still remained forsome time transparent and red as seen through the scales of the
living insect. Moreover, in these cases the meal was generally digested or voided
within about twenty-four hours.
On the other hand, Anopheles which had fed themselves under natural conditions
generally presented a very different appearance. They were enormously distended;
while the contents of the stomach were thick, opaque, and black, and sometimes did
not disappear for three days. The only inference is that, under natural conditions,
the insects which can manage to do so gorge themselves over anil over again during
the night-probably from the same subject.
(3) Propagation.-We also observed that while naturally fed gnats invariably laid
eggs after two or three days, those which had been bred from the larve in captivity,
and had then been isolated and fed in test tubes, never did so, although before being
isolated they had long been in company with males. The inference is that fertiliza-
tion takes place only after the female has been fed.
We noted also that in a cage where many male and female gnats, COdex and Ano-
pheldes, were kept together for weeks eggs were never laid, although the insects were
fed as described on bananas, and the cage contained water for them to lay their eggs
in. It seems, then, that a meal of blood is necessary before fertilization.




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70 ..

Lastly, we observted that previously fed and fertilized inmeta would lay &f j
batch of eggs after a second meal of blood without a second fertilization, but
laid a second batch of eggs without a second meal of blood. That is, one feilafblar
tion suffcie for several batches of eggs, but one meal of blood for only one 'a r.iH
ell-
These observations are wholly in accord with the remults of the proMlonged t lj
many kinds of gnats ti made in India by one of us; and it therefore eems likely. ;iS
the following law is likely to hold good for the CWiidr which feed on men t iii!i.
for the cotmmoner species. .. B
Although thest' gnats can live indefinitely on fruit and perhaps juices of plehittin,.:.,.
female requires a meal of blood, both for fertilization and for the development oa bh::iiaM
ova. In other words, the insects need blood(l for the propagation of their 'pa|esg i "i
Blood was never fo und in male Cu (letide in Freetown, according with the ga..iwu ii.
law -::: ii
(4) Jfauids.-The large majority of Anophele. caught by us in dwelling wi'n l
females which were generally much gorged, and, if fed at all, were invariably EAi.i:i:t.
ized; in other words, the males and unfed, or only slightly fed, female do notga I
rally remain in the houses during the daytime, or if they did remain, kept Ult ::the
roofs or other dark places where they were little observed. On the whole, we think K.::K
that only those females which are so gorged that they can not fly far remain inthl "*I
houses during the day. We observed that if a cage full of Anophdes wa disturbed j..I
in the daytime, the insects always struggled toward the light as if to fly out ftoi. .
the windows, and several which escaped from the cages actually did so. On one .11
occasion a large number escaped from their cage during the night in the rooms oecu ::i
pied, by one of us; none of them could be seen next morning. i
Yet we may be quite sure that both the males and the unfed females haumntthe :
houses during the night. The invariably fertilized conditions of the gorged feimales ':
caught in the houses show that the males must be present in the houses when the
females feed, since the latter are often ,so much distended after feeding that they ae I
obviously unwilling to fly even a few feet front the bed of their victim; in other .ii
words, fertilization must take place within the houses. The unfed females must, ofd.
course, resort to human habitations during the night in order to obtain their food
at all i
These facts would seem to indicate that in Freetown in the rainy sewon the ."
A nap/i.les resort to the houses during the night, but that all except the gorged fe male
live elsewhere during the daytime-possibly sleep in the trees and shrubs. The bs
point is of interest as tending to show that large numbers of Anopheles may be preaent I
in a dwelling during the night, without it being easy to find them during the day. ::
It should, however, le added that in India males and unfed females were often :.
found in the houses in large numbers by one of us. Possibly different species have .!
different habits in this respect.
Several old residents of the country informed us that gnats are usually veryprevl-
lent in the presence of much vegetation-especially long grass and undergrowth. *
Though it is difficult to see how such can favor the larvae, we can understand tt ha
much vegetation can shelter the adults of certain species, which may even feed on .
particular kinds of plants when they can not obtain blood, and may consequently.
find it easier to live where these plants afford them both food and shelter than elme- :|
where. It must also be remembered that gnats can certainly bite birds and other .i
mnamnimalia lbsjdes man; and that such are apt to congregate where there is muckh.i
vegetation. On the whole, then, there is nothing improbable in the idea that the 6 j:
Freetown Anpheliee should live outside the houses in the daytime. ftj
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