130 INSECUTOR INSCITL^ MENSTRUUS 



A local species, confined to the salt marshes of the Pacific 

 coast from San Francisco to San Diego. It is probably to be 

 considered as a derivative of grossbecki; but the differentiation 

 is clearly of a specific degree. 



THE LARVA OF AEDES CAMPESTRIS 

 DYAR & KNAB 



(Diptcra, Culicidce) 

 By HARRISON G. DYAR 



Discovery of this larva was made in April, 1920, in the salt 

 marshes at Garfield, Utah, a station about 15 miles from Salt 

 Lake City. The marshes contain much grass, the water being 

 derived from seepage from mineral springs, and distinctly 

 saline and unpleasant to the taste. The larvae associated in the 

 marshes consisted of a small percentage of niphadopsis D. & 

 K., the remainder being curriei Coq. and camipestris D. & K., 

 the latter present in about 15 per cent of the early emergencies. 



Larva. Head rounded, about as broad as long, light yellow- 

 ish; hairs, upper in threes (varying from two to four), lower 

 single and large. Antennas moderate, spinulated, the tuft at 

 the middle. Skin glabrous. Lateral comb of the eighth seg- 

 ment a patch of about 34 broadly oval scales, fringed with 

 coarse spinules, uniform, except that the terminal spine occa- 

 sionally appears stouter than the rest, but slightly. Air-tube 

 about three times as long as wide, conically tapered, pecten 

 reaching somewhat beyond the middle, of about 30 scales, 

 evenly spaced, the last three stouter and a little more distantly 

 placed than the others, followed by a 4-haired tuft. Anal seg- 

 ment with the dorsal plate reaching about the middle of the 

 side, irregularly edged, pale. Ventral brush with four pre- 

 ceding tufts. Anal gills rudimentary. 



The larva is similar to that of curriei, diflfering in the head 

 hairs, which are normally both single in curriei, and in the 

 pecten of the air-tube, which in curriei has less teeth, the 

 terminal ones not being incrassated. 



