858 MOSQUITOES OF NOETH AMERICA 



Abdomen subcylindrical, rather bluntly terminated posteriorly, fifth, sixth 

 and seventh segments apieally expanded beneath ; dorsal vestiture of dull blue- 

 black scales, an indistinct, yellowish median spot at bases of segments three 

 to six, a series of very large, lateral silvery-white patches at bases of segments, 

 elongated and showing in a dorsal view on fifth, sixth and seventh se.arments, 

 united into a band on eighth segment ; first segment black scaled and with many 

 fine pale hairs; venter yellowish scaled, the apices of segments with broad, 

 apical black bands, eighth segment entirely black-scaled. 



Wings moderate, hyaline; petiole of second marginal cell less than half as 

 long as its cell, that of second posterior cell about as long as its cell, basal cross- 

 vein distant about its own length from anterior cross-vein ; scales brown, those 

 on costa with a blue reflection, the outstanding ones linear, broader and denser 

 on second vein. Halteres whitish, knobs dark at their bases. 



Legs slender, moderately long; vestiture black; femora whitish at base and 

 narrowly beneath to tips on middle and hind pairs, nearly to apices on front 

 pair; knees silvery-white scaled, broadly on hind pair; fore tibiae with a silvery 

 spot dorsally at apex ; hind tarsi with the first three joints broadly white ringed 

 at base ; mid tarsi with the first two joints narrowly white ringed ; front tarsi 

 entirely black. Claw formula, 0.0-0.0-0.0. 



Length : Body about 3.5 mm. ; wing 3 mm. 



Male. Proboscis straight, rather long and slender, brownish-black scaled. 

 Palpi longer than the proboscis, very slender, uniform, terminal joints with a 

 few stiff setae; vestiture brownish black, a pale ring before middle of long joint. 

 Antennae plumose, the last two joints long, slender, rugose, pilose, black, the 

 others short, luteous, ringed with black at insertions of hair- whorls; hairs of 

 whorls long, dense, brownish-black. Coloration similar to the female. Abdomen 

 elongate, somewhat expanded to sixth segment; seventh and eighth segments 

 dorsally with silvery basal bands; lateral ciliation coarse, rather sparse, yel- 

 lowish. Wings scarcely narrower than in the female, the vestiture less abun- 

 dant. Claw formula, 2.1-3.1-0.0. 



Length : Body about 3.5 mm. ; wing 2.5 mm. 



Genitalia (plate 32, fig. 218) : Side-pieces about twice as long as wide, tips 

 rounded ; apical lobe absent, basal lobe semi-detached, slender, conical, bearing 

 a stout articulated spine at tip. Clasp-filament slender, long, with a long articu- 

 lated terminal spine. Harpes broadly ligulate, margins revolute, tips recurved 

 and cleft. Harpagones wanting. Unci contiguous, revolute, forming a large 

 basal cylinder. Basal appendages represented by three spines on either side. 



Larva, Stage IV (plate 125, fig. 434). Head rounded, slightly narrowed 

 before eyes, a slight notch at insertion of antennae, front margin arcuate ; an- 

 tennae slender, rather long, smooth, a single hair at middle, four unequal spines 

 and an articulated digit at tip; upper pair of dorsal head-hairs double and 

 rather long, lower a pair of ample tufts, ante-antennal tufts of five hairs. 

 Thorax subquadrate, the lateral hairs coarse, moderately long and abundant. 

 Abdomen rather long, the lateral hairs in threes on first segment, double on 

 second to sixth segments ; secondary hairs of coarse stellate tufts both dorsally 

 and ventrally. Comb of eighth segment of a long regular row of closely placed, 

 long, spine-like scales. Air-tube slender, about five times as long as wide; 

 pecten of long, evenly spaced teeth running to near middle of tube and fol- 

 lowed by a single tuft of two hairs. Anal segment longer than wide ; dorsal 

 plate quadrate, reaching over half-way down the sides, two groups of long spines 

 projecting from near posterior margin ; a single lateral hair at posterior angles 

 of plate ; dorsal tufts a long hair and tuft of long hairs on each side ; ventral 

 brush well developed, the tufts long but rather sparse ; anal gills short. 



