768 MOSQUITOES OF NORTH AMERICA 



Abdomen subcylindrical, tapering posteriorly; dorsal vestiture blue-black, 

 with brown bristles at ends of segments, a series of basal, triangular, dull yel- 

 lowish-white, lateral segmental patches extending well towards apices of seg- 

 ments; first segment with a large patch of dirty white scales and many fine, 

 pale hairs; venter sordid white, with ill-defined, apical, median black spots, 

 most extensive on last two or three segments. Cerci black. 



Wings rather broad, hyaline, slightly inf uscated ; petiole of second marginal 

 cell shorter than its cell, that of second posterior cell also somewhat shorter than 

 its cell ; basal cross-vein about its own length distant from anterior cross-vein ; 

 scales on veins black, the outstanding ones narrowly ligulate, broader at apices 

 of veins. Halteres whitish, with darker knobs. 



Legs moderate; femora sordid-yellowish below, intermixed with black scales 

 above, which predominate towards tip ; knees yellowish-white scaled ; vestiture of 

 tibiae and tarsi black with dull bronzy luster; tips of tibias slightly yellowish. 

 Claw formula, 1.1-1.1-1.1. 



Length : Body about 5 mm. ; wing 4.5 mm. 



Male. Proboscis moderately long and slender, black scaled. Palpi slightly 

 longer than proboscis, entirely black scaled; last two joints and end of long 

 joint slightly thickened and with dense, long brown hairs. Antennae plumose, 

 the last two joints long and slender, rugose, pilose, black, the others pale, black 

 at insertions of the hair-whorls; hairs long, dense, black with bro'wai luster. 

 Coloration similar to the female. Occiput broadly yellowish-white scaled. Ab- 

 domen elongate, depressed ; segments with large, subquadrate areas of pale scales, 

 contiguous with base and apically indented, the sides continuously yellowish- 

 white ; venter whitish-scaled, with broad, nearly continuous, black median stripe, 

 only slightly interrupted at bases of segments; lateral ciliation long, dense, 

 regular, pale brown. Wings narrower than in the female, the stalks of the fork- 

 cells longer, the vestiture less abundant and paler ; scales on forks of second vein 

 much broadened. Legs longer than in the female, the tibiae and tarsi with brassy 

 luster beneath. Claw formula, 1.1-1.1-1.1. 



Length : Body about 5 mm. ; wing 4 mm. 



Genitalia (plate 29, fig. 196) : Side-pieces over twice as long as wide, conical ; 

 apical lobe large, conically prominent, continued narrowly to base, where a large, 

 stout spine indicates the basal lobe, a tuft of long very dense setae at tip of side- 

 piece. Clasp-filament long, slightly swollen in the middle, apex dentate and 

 bearing three short setse, a terminal articulated spine. Harpes elliptical, con- 

 cave, inner margin thickened and revolute, tip pointed and recurved. Harpa- 

 gones with a slender columnar base which has a blunt projection at outer fourth, 

 bearing a small seta and minutely pilose, and apically with a long ligulate articu- 

 lated filament, as long as stem and pointed at tip, with a sharp retrose branch 

 beyond the middle. Unci approximate, revolute, forming a small basal cylin- 

 der. Basal appendages approximate, bearing four short stout spines. 



Larva, Stage IV (see figure of the entire larva, plate 72). Head broad, sub- 

 quadrate, hind angles rounded, slightly narrowed before eyes, a broad notch at 

 insertion of antennas, front margin broadly arcuate. Antennae very long, longer 

 than head, outwardly curved at the middle, basally swollen, attenuated towards 

 tip, covered with rather long spines; a large tuft beyond middle; three long 

 coarse spines at tip and a short digit. Eyes large, transverse, pointed. Both 

 pairs of dorsal head-hairs double, ante-antennal tuft multiple. Mental plate 

 triangular, as broad as Jong, the terminal tooth projecting ; nine side teeth, large, 

 rather closely set, becoming more distant at base. Mandible quadrangular, wide 

 at tip ; a few short spines without at base ; two long filaments toward tip ; an outer 

 row of stout cilia ; nine filaments on outer edge, the terminal ones partly decum- 

 bent, basal ones with branching hairs; dentition of four teeth on a process, a 



