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Psyche 10:1-6, 1903.

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PSYCHE
A JOUR3SrA.L OF ENTOMOLOGrY
[Established in 18741 ,
Vol. 10, No. 321
CONTENTS
A CONTRIBUTION TOWARD A KKOWLEDGE OF THE LIlV2 HISTORY OF CUI.EX SOLLICI- TANS. Plate I.- John B. .Smith , . , . . . . . . . 1 CLASSIFICATION OF THE GALL-WASPS AND THE PARASITIC CVSII'OII)S, OR THE SUPER- FAMILY CYNIPOIDEA. I.- William H. d~fiwi-Cad . . . , . , . 7 LIFE HISTORIES OF NORTH AMERICAN GEOMETRIDAE. XXXIX.- firri~oii G. D-I?II' 15 ~ INSRCT PSYCHOLOGY. - Justus Watson Folsom . . . . . . . . . 15 SOME SPECIES OF EULECANIUM (COCCIDAE) FROM FRASCE. - T. D. A. Cockcre~ . . 19
BUTTON-BUSH INSECTS. -James G. Neediim . . . . . . . . . 22 THE HEMIPTERA DBSCRIDIHO BY PHILIP REESE UHLEK. 1.- Sllllt!~l Hens/law . , 31 REVIEWS.-Blatchley : A nature wooing at Ormoncl by the Sea. A. P. Morse. Kieft'er : Monographic des cynipides d'Eiirope et d'Alg6rie.- Wm, H, Ashmend . , 4.3 PUBLISHED BY THE
CAMBRIDGE ENTOMOLOGICAL CLUB
CAMBRIDGE, MASS., LJ. S. A.
Pu&e 10:001-9 (1933). hup Ytpsycht enlclub orgti WlO-OOOOl hlml



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Psyche, Vol. 10.
Plate I.
-
SMITH :-CULEX SOLLICI'I ANS W1.K.




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PSYCHE.
A CONTRIBUTION TOWARD A KNOWLEDGE. OF THE LIFk HISTORY OF CULEX SOLLICITANS. PLATE 1.
BY JOHN S. SMITH, NFW BRUSSWICK, K, J
The life history of a mosquito is ordinarily supposed to be rather a simple affair, and when egg, larva, pupa, and adult arc known and the stage in which the winter is passed, it is assumed that little more remains to be learned. Yet of at least one species this is so little true, that our knowledge of the ordinary life cycle is a mere introduction to a real history of the species. The species referred to is Cnlex so/Z/c/å´'/ Wlk., which breeds abundantly along the shore districts in New Jersey, and which I have had under close obser- vation during a portion of the season of 1901, and almost the entire season of 1902. Yet after carefully reviewing the results of the work clone and the observations made, it appears that there is at least one full season's work yet required to clear up the questions left unsolved or raised by what has been already learned, The salt-marsh mosquito is, from the economic standpoint, the most important species that occurs in New Jersey, and it is of New Jersey conditions that I intend to speak here.
It dominates the entire southern half of the Slate and occurs in
swarms where there is no chance of mosquito breeding for miles about, except in casual rain pools - and there the larva is never found. 1 do not mean to contra-
dict observations made elsewhere, or lo question conclusions drawn from such observations : I mean only to state actual facts and the deductions I make from them! It is quite possible that elsewhere, under other climatic conditions, these deductions may piove incorrect ; but it will need equally extensive observations to demonstrate this.
The species passes the winter in the egg stage. This is demonstrated nega-
tively by a failure to find adults at any time during the winter in quarteis whore the species is dominant, and where other species of CULEX and ASOPHELES may be found.
Positively it is proved by the tact that very early in spring; swarms of minute larvae appear in winter-filled pools, as soon as the temperature reaches 50' Fahrenheit or over, and when not an adult can be found on the closest search. Early in April (4) larvae pretty well grown were found in Cape May County in pools, high above ordinary or even summer storm tides, formed by the heaviest



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2 P.5- YCHE [February
winter storms and already drying down. These were fotind after a day of search for adults in which Culexpunge/is and (probably) C rest-nans and Anophelespuiicfi- pennis were found; but no C. so/Zic//ans. The same story was repeated on the 11th; and on the 19th and zoth, as the advance of the season cut off pools and ditches from tide connection, it was quite interesting to watch the appearance of the baby larvae in pool after pool and ditch after ditch. A pool in which on the afternoon of the 18th there was no trace of larvae, about which not an adult could be stirred up, swarmed with minute larvae on the morning of the 19th. They had hatched during the night, from eggs that were already in the water and that required only the proper temperature to bring them out. This pool had been severed from the tide not over 48 hours and the result- ing uniformity of temperature was sufficient to produce the proper condition tor the larval life. At this time the temperature of the sea water in a creek at halt tide was po. The temperature of the pools in which the young larvae appeared was 5z0, and the older pools in which larvae were nearly full grown were at s4", all I"ahrenheit.
A very suggestive condition of affairs was found in a low meadow well above tide level, which had become filled with snow and rain and by drainage and formed a shallow pond about 4 acres in area. 1 know positively that this area was dry except in one low corner during the entire season of 1901 between May 1st and September I sth, and 1 am informed and believe that it remained dry until late December.
At all times during the summer the meadow swarmed with C. so/Zici- tans and now, April 18, 1902, this entire area was inhabited by larvae of that species already nearly full grown; some, indeed, in the more sllallow areas were already in the pupal stage. Obviously the eggs must have been laid in the dry meadow during the summer, for at no time when mosquitoes were flying was there any water to lay them into.
A large number of adults was bred from larvae gathered from pools ot all kinds, ranging from fresh to vciy salt water and, except in one instance, only C. sollidtans was bred. The exception was a single lot of larvae from a pool of brackish water from which C cantans was also obtained. The larva of C. .so/licitnns is light slate gray in color, the head yellow, without markings of any kind, anal siphon short and stout, antenna short, slender, black at the tip, without obvious set off or prominent tufting. The figure (111. I, fig. I) shows very fairly the appearance of the larva; the shape of the head and especially of the vertex being quite characteristic. Several other larvae resemble this and are not readily separable - notably those of C. cantans and C. laeniorhy~~chus. What happened in Cape May County between April 20th and June isth, when next I went there, I am unable to say; but the season had been very dry,



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pools were everywhere much reduced, swarming with larvae and pupae, while thc grass was filled with males. There were very few females and evidently, of the new brood just coming to maturity, only the males had yet emerged. A month later only a few bodies of water remained and they were drying up fast - so fast indeed, that thousands of larvae failed to come to maturity, and the half or quarter inch of water remaining in some pools was one squirming, wriggling mass. A systematic search was now made for the eggs and they were found in quan- tity after the right places were determined. Of the older females, flying July 8-20, almost all contained eggs, ranging from soft, white, through pearly, translucent, as the shell formed. to b1:iclz. Black eggs only were found in the meadows, well above the recent water line of such pools as yet remained, in the black mud in which their color made them almost invisible. It has been recently snggestecl that black is an unusual or exceptional color for mosquito eggs and that the habit of ovipos- king on land rather than water is exceptional. This may be true for Louisiana where the observations leading to that suggestion were made; but in New Jersey C. sollicitam certainly lays black eggs in black mud. No other color would do so well under the circumstances ancl, outside the body of the mosquito, I never saw C. sollii-itam eggs other than black ! From a piece of sod about 4 inches square I washed the surface nrud into a basin of water, waited until the whole settled to the bottom, to make certain that the eggs did not float, and next morning J had over 300 and possibly 500 lively young wrigglers. It is important to note, in this connection, that though Mr. E. I,. Dickerson (my assistant) and I collected several hundreds of specimens of mosquitoes betwecn July 8th and 20th no examples of C. fae~zio-~~h~v~c/z?~s were sccn, nor had I at any time previously in 1902 collected C. tmiorhynchiis near this point. Neither was that species bred out of any larvae taken from the pools where we were then experi- menting.
Two large sods were cut out of the marsh, well above any recent pools, and these were carried to New Brnnswick to serve for laboratory tests. One sod was kept entirely dry, the other was kept constantly moist though never covered wit11 water. The presence of eggs in both sods was demonstrated by actual examination and, at intervals, small pieces of sod were covered with water and the results were noted. From the dry sod larvae were always obtained in a short time-from one half to one hour; from the, wet sod no larvae were obtained ancl all the eggs found were burst.
Two lots of larvae from the dry sod were bred to niatnrity and all the adults proved C. taetziorhynchii.s! The larvae were those of C. sol?icitans except that they seemed undersized ; but the adults were unquestionably the other species. Finally, September 21, two n~onths after I took it up, I placed the remnants of the moist sod



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4
PSYCHE [February
in a large dish of water and next morning, to my great surprise, I found a fair lot of larvae.
Out of these I obtained 8 adults and of these three were undoubted so//i~~itms.'
It is a fair suggestion that there is something yet to be learned con- cerning the relationship between C. soZ/icifms and C fae?zim+ydzzis. The season at the point where the collections were made was phenomenally dry and all pools and ditches remained dry until September 5 or 6, when a heavy storm filled everything. On the iitli, Mr. Dickerson investigated, found every pool swarming with recent larvae, and brought up 20 small sods from ten separate places well above the pool line and which had been entirely dry since early July and probably a month before that date. All but two of these sods had been tested and had shown the presence of eggs, hence it was a fair conclusion that eggs were generally distributed all over the meadow. From eight of these sods larvae were bred in the laboratory.
The eggs are spindle shaped just a little curved, shining, and when the larva batches the upper & lifts off as if by a hinge. Anothe~ obseivation made ~t Beach Haven early in August ~IHOWS further light 11pon the egg-laying habits of the species. A very heavy rain after a long
dry spell, followed by a series of shovicis ci~11-ing which 3 or 4 inches of rain fell, lillcd every low area in the meadows with from 5 to J$ inches of water. Within wenty-fonr hours this entire area was swarming with larvae jnsi hatched and in forty-eight hours millions had perished because the water had disappeared: evap- orated by the hot sun or soaked into the parched soil. It would be easy to add to this further observations, all tending to the point thai the Female oviposits almost anywhere in the meadows, at the base 01 grasses; but it would seen1 as if tlie above were sufficient.
I stated that, in early J~ily, tlieie was no trouble in finding gravid females and: indeed, almost all the femalcs t.ilien nere full of eggs. It is a curious fact
that this coridii-ion was not agri-in duplicated later in the season. Fiom the beginning of Septembel to the middle of October collections were made daily on the Newark meadows! and from that time to the end of mosquito flight in November, collections were made at least once'and usually twice a week. Yet of the many hundreds of examples dissected not one contained mature eggs. ~ ~
After a long period of drought which left the upper part of the Newark n~eadows dry, C soi/icitous became very scarce in early September. On the night of the
4th and 5th there was a very heavy tide that flooded the meadows to the edge of the City, and covered the marsh tract at the mouth of the Elizabeth River. On the 6th Mr. H. H. Brehme, who made the meadows investigations for me, found everything swarming with recently developed larvae which grew rapidly as the pools gradually dried up. By the 16th almost the entire brood was mature and



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the pools were crowded with pupae and a small proportion of full grown larvae. The grass was now full of adults which made life almost unbearable unless some method was used to keep them off. The practical disappearance of the earlier broods before the new brood issued fixed the age of these specimens and there was no oher general brood that developed later on these meadows. I thought this a good opportunity to ascertain how long a time it would require for eggs to develop and 11:nce had the collections made daily for some time. Vet. at the end of the season 1 had no evidence that even one example out of the entire brood laid even a single egg ! Lot after lot was received with absolutely undeveloped ovaries and not even a single example was found having eggs ready to be laid ! The question is, did they lay any at all? In sods collected after the water had drained off none were found, and practically I do not know ;vheie the eggs are that will start C. sdhci1ans next spring. Dr. Dyar has suggested, in connection with another species, that of eggs laid in spring' some might hatch during the summer but that others would lie over until the season following. It is, of course, possible that the same thing occurs in this case and th.it unhatched eggs are yet on the meadows, ready to develop under favorable conditions next spring. As to the number of eggs laid by a female, the dissections made gave an average of about 17s. A very few reached 200 and very few had less than i,jo unless the n~unber was very small.
Another peculiarity of C. siilfu-itens in New Jersey is, its habit of travelling long distances inland, either by flight or by allowing itself to bc carried by the pre- vailing winds.
After the middle of July the entire pine region of South Jersey gradually fills up with these insects, sometimes swarming miles from any water and forty miles from any point where C. soliicitans larva has ever been found. On two occasions I made systematic search during two or three clays, over a large area where C. soZiicitans was the dominant species, finding larvae of forms whose adults escaped attention, but none of the shore species. Nor did I ever find in the pines even one adult example in which the ovaiies were at all developed. August idth, I captured 253 examples in one area in Ocean County, by sweeping so as to get old, inactive specimens, and not one of these had the ovaries in the least devel- oped. A lot of 90 was captured a few days before by picking [.hem from the coat of the collector and these were found in a similar undeveloped condition. I omitted to mention that in these flights, so far away from home, the males have no prt -only the females wander. It is quite certain that none of the millions of these mosquitoes that infest the Jersey pines ever reproduce, because the surround- ings are not suitable; and it is almost equally certain that they could not if they had the opportunitj7, because the ova simply do not develop. The life period of the individual of this species is not determined; but it is



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6 PSYCHE [February
probably of considerable length, especially in those forms that do not reproduce. that they may bite more than once is certain, and direct experiment has proven that a full meal of blood may be so completely digested in one week, that scarcely a trace remains. The examination of a large number of specimens seems to indi- cate that blood food stimulates ovarian development, for in the great majority of cases wliere I found fully developed ova I found also blood remnants. In those
cases in which such remnants were not found it cannot be safely concluded that such food had not been taken more than a week previously. But I did find numer-
ous instances of ova starting development where the alimentary canal contained only a colorless liquid; probably plant juices. Larvae of C. soliicitans were not found after November 4, but adults continued until well along in that month. In shelters along the Newark meadows where C. /~&ititSiis, another salt water species, was found hibernating, not a C. solliciians occurred in December.
Altogether the life cycle of this species offers points of interest that will require at least another full year to work out. I. Full-grown larva.
2. Pupa.
3. Adult male, From above.
4. Adult female, from side.
5.
Head of larva from beneath.




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