MOSQUITOS OR CULICIDAE OF NEW YORK STATE 345 



Life history and habits. This species is neither common nor 

 troublesome, according to Dr Dyar. The larvae were found in a 

 large pool near a cold stream and in a warm marshy pool at Bell- 

 port L. I., occurring sparingly here and there. Both places were 

 permanent bodies of water and contained aquatic plants. The eggs 

 are deposited as a boat-shaped mass, which floats on the water, 

 much as Oulex pungens, but the mass is smaller, contains 

 fewer eggs and is less regularly elliptic. The normal feeding 

 position of the young larva resembles Culex, but the body is more 

 nearly parallel to the surface. The larvae are fond of resting 

 under the leaves of Lemna, where they remain with the air tube 

 penetrating the surface film. There appear to be four larval 

 stages, and the species seems to breed throughout the summer, 

 preferring warm, stagnant pools of some size containing 

 Spirogyra. 



This subfamily includes some very interesting forms which have 

 been largely neglected, probably on account of their relatively 

 slight economic importance and also because of their retiring 

 habits. So far as known, all are predaceous and therefore more 

 or less beneficial. Among them we find a most efficient destroyer 

 of mosquito larvae, Eucorethra underwoodi, which is 

 unfortunately a form of small value because of its extremely 

 local habits, since it appears to be confined almost entirely to 

 very cold spring pools in deep woods. The peculiar, nearly trans- 

 parent, phantomlike larvae of Sayomia belong here, and the still 

 more interesting Oorethra larvae, which appear to be inter- 

 mediate in structure between those of Sayomia and Culex, are 

 also members of this subfamily. Eucorethra has been known only 

 since 1900, and Corethrella, repTesented by a species with very 

 interesting habits, is a more recent discovery. 



Key to genera 



a First tarsal segment longer than the following segment 



6 Species less than tb in. in length; tarsal claws simple 



G Antennae verticillate with hairs i. e. in whorls. . . . Sayomyia 

 cc Antennae wholly covered with hairs, legs densely 



haired Corethrella 



b& Large species % in. or more in length ; tarsal claws bifid. Eucorethra 

 aa First tarsal segment shorter than the following segment Corethra 



