AQUATIC INSECTS IX NEW YORK STATE 



381 



Larva. Specimens from Wilmuth and Axton N. Y. [P1.37, 

 fig.l to 6]. Pale brown with paler incisures; head brown, lab- 

 rum hairy, with serrated edge; fans with 50 to 60 rays; man- 

 dibles with a pair of apical setae; hvpopharynx as usual; labrum 

 [fig.6] with middle tooth rather prominent, its ventral surface 

 with five setae in each of the two rows; each of the three 

 branches of anal papillae with a number of lobes. 



Pupa. Six branched respiratory filaments; eight hooks curved 

 cephalad on dorsum of each of abdominal segments 3 and 4; 

 four hooks curved cephalad on ventral surface of each of seg- 

 ments 5, 6 and 7; a close transverse row of small caudad pro- 

 jecting spines on dorsum of eighth segment, and a pair of short, 

 blunt tubercles on the anal segment. Cocoon of the wall pocket 

 type. 



S. venustum, var. a 



Plate 37, fig.8-14 

 A number of specimens bred from larvae and pupae taken 

 from Fall creek, Ithaca N. Y., differ in the adult stage from 

 venustum as described above in being uniformly smaller 

 (length 1.5mm); having the base of wing brownish and not yel 

 iow, and in having the last fouv abdominal segments of the 

 female a shining black instead of brown. The larva differs as 

 follows: in size averaging less than two thirds that of venus- 

 tum, labrum with its toothed edge wider in proportion to its 

 size than in venustum, its teeth more nearly of a size, 

 the ventral setae three in each row plus a very small one. The 

 pupa differs in having 10 respiratory filaments in each tuft, 

 the hooks on segment 2 more distinct, and the tubercles on the 

 anal segments apparently wanting. 



S. piscicidium (Synonym of venustum) Riley 

 Am. Ent. 2:367 

 According to Coquillett this is a synonym ofS. venustum; 

 but I have larvae and pupae from Professor Needham, taken 

 at Saranac Inn N. Y., which, though agreeing with Riley's fig- 

 ures of piscicidium, differ decidedly from the larvae and 

 pupae of S. venustum taken by Messrs MacGillivray and 

 Houghton at Axton N, Y. in 1901, and by Professor Comstock 

 at Wilmuth N. Y. Of the adults of the Saranac Inn material 

 I have only alcoholic specimens, hence can not state definitely 

 wherein these differ from S. venustum from Axton N. Y. 

 excepting that it averages a little larger in size. For the pres- 

 ent I shall regard it as a variety, though in all the material 



