772 MOSQUITOES OF NORTH AMEEICA 



brown line followed outwardly by narrow silvery stripes, broader medianly and 

 angularly produced at the middle; anteseutellar space narrowly bordered by 

 silvery scales. Scutellum trilobate, gray, with silvery scales, each lobe with a 

 group of brown bristles. Postnotum elliptical, prominent, brown, nude. Pleurae 

 brownish, coxae luteous, clothed with patches of flat, broadly triangular white 

 scales and rows of golden bristles. 



Abdomen subcylindrical, flattened, tapering posteriorly; dorsal vestiture 

 black with brown luster, a series of lateral, basal, segmental, triangular, yellow- 

 ish-white patches, largest on sixth and seventh segments; first segment with 

 patches of black scales and with many long, fine, pale hairs ; venter white with 

 the apical lateral angles of segments black. Cerci black. 



Wings moderate, hyaline; petiole of second marginal cell somewhat shorter 

 than ite cell, that of second posterior about equal to its cell ; basal cross-vein dis- 

 tant about its own length from anterior cross-vein ; scales brown, the outstand- 

 ing ones narrowly ligulate. Halteres whitish, with pale knobs. 



Legs moderately long, slender; vestiture dark bronzy brown; under sides of 

 femora yellowish- white nearly to the tips ; tibiae and tarsi with paler luster be- 

 neath. Claw formula, 1.1-1.1-1.1. 



Length : Body about 4.5 mm. ; wing 4 mm. 



Male. — Proboscis straight, moderate, dull brown scaled. Palpi exceeding the 

 proboscis by nearly the length of the last joint ; vestiture entirely blackish-brown 

 with submetallic luster ; end of long joint and the last two joints slightly swollen, 

 with long, dense black hairs. Antennae plumose, the last two joints long and 

 slender, rugose, pilose, black, the others short, pale, with black rings at in- 

 sertions of hair-whorls ; hairs long, dense, dull brown. Coloration similar to the 

 female. Abdomen elongate, depressed, with large, lateral, basal, segmental, 

 white patches, very large on the sixth and seventh segments, the last segment 

 entirely white scaled ; lateral ciliation of abundant long, fine, pale hairs. Wings 

 slightly narrower than in the female, the stems of the fork-cells longer, the 

 vestiture sparse. Claw formula, 3.1-3.1-1.1. 



Length : Body about 5.5 mm. ; wing 4 mm. 



Genitalia (plate 39, fig. 198) : Side-pieces about three times as long as wide, 

 rounded at tips ; apical lobe rounded, low, not reaching far toward base ; basal 

 lobe low, but bearing fine hairs and a large, very stout curved spine. Clasp- 

 filament long, slightly swollen mesially, with a long articulated terminal spine. 

 Harpes elliptical, concave, tips thickened, pointed, curved. Harpagones with 

 long, rather slender columnar stem, smooth, uniform ; terminal filament with a 

 lateral expansion which has four to five sharp retrose spines, its tip roundedly 

 pointed. Basal lobes well separated, small, rounded, each with three short seta. 



Larva, Stage IV (plate 119, fig. 413). — Head rounded, widest through eyes; 

 antennae rather small, uniform, spinulated, with a small tuft before middle; 

 both pairs of dorsal head-hairs single, ante-antennal tuft multiple. Body with 

 the skin pilose. Lateral comb of eighth abdominal segment of numerous scales 

 in a triangular patch, each scale with long central spine and long lateral fringe. 

 Air-tube about two and a half times as long as wide, slightly tapered outwardly; 

 pecten of about seventeen evenly and closely set teeth, reaching to near middle, 

 followed by a single tuft of about eight hairs. Anal segment slightly longer 

 than wide, ringed by the plate ; dorsal tuft a long hair and tuft on each side ; 

 lateral hair single, small ; ventral brush well developed, confined by the chitinous 

 ring; anal gills long, thick at base, tapering to flne points, equal. 



The larvae live in temporary ground-puddles. Mr. Knab got them in puddles 

 in a stream-bed, associated with Psorophora posticatus, Culex proclamator, 

 Psorophora ciliata, and Psorophora virescens; in a pool of clear water in a 

 stream-bed, associated with Culex derivator, Culex pinarocampa, and Anopheles 



