178 AGRICULTURAL EXPERIMENT STATION. 



The anal siphon is large, thickest near the base, narrowing con- 

 siderably apically and is about four times as long as its greatest 

 width. There are from twenty to thirty spines in each of the 

 lateral rows, the single spines very long and slender (fig. 52, 

 5), with one or two teeth at the extreme base. The ninth seg- 

 ment is slightly longer than broad, with a very short double dor- 

 sal tuft and ventral brush, the latter not issuing from a barred 

 area and the tufts extending the whole length of the ventral bor- 

 der. The tracheal gills are long, about three and one-half to four 

 times the length of the ninth segment. 



*b' 



Habits of the Early Stages. 



The eggs of this species are laid at the edge of a pool or, per- 

 haps more usually, in a moist depression, where they remain dor- 

 mant until they become water covered. They are of considerable 

 size, coarsely sculptured and hatch within a few hours after the 

 pools become water filled. Eggs have been obtained from fe- 

 males which have been allowed to bite so as to obtain blood food, 

 and the indications are that blood food is essential to the insect 

 for ovarian development. Mr. W'inship has sent in eggs and very 

 young larvje, dipped from a pool at Monmouth Beach. They 

 were, apparently, resting loosely on the layer of bottom mud and 

 rose when the dipping was in progress, so that quite a number 

 were obtained. 



Mr. Seal reports the hatching of the eggs very soon after a pool 

 becomes water filled, and the rapid development of the larva. 

 "On one occasion it began to rain on Monday morning- and water 

 soon collected in the bed of a dried-up pond. In the deepest 

 place there was a patch of damp mud with a rotten log lying in 

 it. On Tuesday there were thousands of Cidex (syhestris) 

 larv?e about one-eighth of an inch long. Pup?e of both forms 

 had developed by Friday, and on Monday all had enlarged." 



The larv?e are immense for wrigglers and are at once recog- 

 nizable by their size. Unlike others of this series they are preda- 

 tory and feed on other mosquito larvK ; if there are not enough 

 of other kinds present they turn cannibals and eat each other un- 

 til some are full grown and complete their transformations. 

 Their appetite is enormous and they feed continuously. Small 

 larvfe are swallowed entire; the larger are seized just below the 

 anal siphon or breathing tube to choke them, and when the strug- 

 gles cease are devoured to the head. The larvae are, therefore, 

 scattered as compared with those of other mosquitoes. Mr. Seal 

 makes it as about one to one thousand of Culex when both occur 



