542 MOSQUITOES OF NORTH AMERICA 



Descbiption of Female, Male, and Larva of Psokophoea vibescens : 



Female. Proboscis slender, about as long as abdomen, uniform, labellae small 

 and tapered ; uniformly covered with black scales and numerous small bristles. 

 Palpi over one-third as long as the proboscis and similarly clothed; bristles, 

 especially toward base, longer. Antennas slender ; shaft ciliate ; tori subspherical, 

 dark brown ; hairs of whorls sparse, short, black. Eyes bronzy black. Occiput 

 blackish brown, with a narrow bare line along median suture, rather densely 

 clothed with broad, white curved scales and with rather numerous short blackish- 

 brown bristles. Clypeus elongate, prominent, rounded, convex, tip subtruncate, 

 shining, brown, nude. 



Prothoracic lobes prominent, moderate, remote, yellowish, with many short 

 black setje. Mesonotum fairly prominent before, arcuate, blackish brown 

 medianly, lighter brown at the sides ; a narrow, median longitudinal line, termi- 

 nating before ante-scutellar space, clothed principally with small black scales 

 and a double series of short pale-brownish bristles; on either side of this a 

 broad bare stripe showing the shining blackish integument ; bordering the bare 

 stripe outwardly a narrow line of dark scales and bristles similar to median 

 line and extending from anterior third of mesonotum to base; anterior angles 

 devoid of scales; immediately within this bare area is a broad, anteriorly 

 pointed, band of broad white scales reaching to roots of wings; a large basal 

 median patch of white scales involving ante-scutellar area, a broad bare stripe 

 on each side of it; hairs at sides of disk coarse, black. Scutellum trilobate, dark 

 brown, each lobe with numerous black setae and a few white scales behind, most 

 abundant on mid lobe. Postnotum elliptical, nude, blackish, slightly pruinose. 

 Pleurae blackish, yellowish in front, largely covered with elliptical, flat white 

 scales mixed with short pale setae. Coxaj yellowish, with a line of black setae, 

 each with a large patch of white scales at base, on the anterior pair followed by a 

 few black scales with blue luster. 



Abdomen subcylindrical, flattened, posterior segments tapered ; clothed dor- 

 sally with black scales which have a bright greenish-blue reflection ; the last two 

 segments paler with silvery and coppery iridescence ; a row of lateral segmentary 

 white stripes, joined into continuous lateral bands, widening somewhat at bases 

 and apices of the segments ; first segment clothed dorsally with white scales and 

 with many brown hairs ; venter clothed with pale brown and white scales inter- 

 mixed, a median basal spot of black scales on each segment. 



Wings rather narrow, smoky, somewhat darker on costal half; petiole of 

 second marginal cell shorter than its cell, that of second posterior cell about 

 equal to its cell ; basal cross-vein distant less than its own length from anterior 

 cross-vein ; scales of veins small, brownish black, the outstanding ones on the 

 veins long and narrow. Halteres with pale stems and blackish knobs. 



Legs long, slender, nearly completely devoid of outstanding scales; femora 

 ochraceous, clothed with short appressed shining yellowish scales, a broad apical 

 ring of raised black scales with a violet-blue luster; tibiae clothed with black 

 scales with violet-blue luster, raised on distal portion, a line of bluish silvery 

 scales at base beneath ; no white knee-spots ; vestiture of the tarsi of appressed 

 scales, black with a faint blue luster, slightly raised on the hind tarsi and with 

 white spots at bases of first and second joints. Claw formula, 1.1-1.1-1.1. 



Length : Body about 7.5 mm. ; \ving 6 mm. 



Male. Proboscis slender, uniform, straight, black. Palpi exceeding the pro- 

 boscis by a little more than the length of the last joint only ; last two joints about 

 equal, thickened ; long joint with a bare false articulation before the middle ; 

 vestiture black with a blue luster and numerous long setae at end of long joint 

 and on the two terminal ones. Antennae plumose ; last two joints long, setose, the 

 others short, whitish, with thick, black rings at origins of whorls; hairs of 



