780 MOSQUITOES OF NORTH AMERICA 



lum trilobate, clothed with silvery-white scales, each lobe with a group of brown- 

 ish-black bristles. Postnotum elliptical, prominent, brown, nude. Pleura? pale, 

 with brown spots, coxas pale, clothed with patches of elliptical flat white scales 

 and rows of pale setae. 



Abdomen subcylindrical, tapering posterior; dorsal vestiture of brownish 

 black scales with faint metallic reflection, with large lateral, basal, segmental, 

 triangular Avhite patches ; first segment with a patch of dark scales and many 

 fine, pale hairs : venter wholly whitish scaled. Cerci black. 



Wings moderate, hyaline ; petiole of second marginal cell about half as long 

 as its cell, that of second posterior cell shorter than its cell ; basal cross-vein 

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

 outstanding ones narrowly ligulate, broader and denser towards tip of wing. 

 Halteres whitish, with dark knobs. 



Legs slender, moderately long; vestiture dull bronzy brown with a bluish 

 reflection ; femora pale whitish beneath, except at tip. Claw formula, 

 1.1-1.1-1.1. 



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



Male. Proboscis rather long and slender. Palpi exceeding the proboscis by 

 nearly the length of the last joint; end of long joint and last two joints slightly 

 swollen and with abundant long brown hairs ; vestiture entirely bronzy brown. 

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

 others short, narrowly black-ringed at insertion of hair-whorls, pale beyond ; 

 hairs long, dense, lustrous broAvn. Coloration similar to the female, the dorsal 

 silvery area of the thorax broader, practically covering the disk. Abdomen 

 elongate, depressed, densely hairj'^ laterall3\ Markings of the abdominal seg- 

 ments silvery, forming broad bands across the dorsum. Wings slightly nar- 

 rower than in the female, the stems of the fork-cells much longer, the vestiture 

 sparser. Claw formula, 2.1-2.1-1.1. 



Length : Body about 3 mm. ; wing 2.5 mm. 



Genitalia (plate 31, fig. 208) : Side-pieces over twice as long as wide, 

 rounded at tip, apical lobe absent, basal lobe small, rounded, prominent, densely 

 setose, with a long stout spine within. Clasp-filament slender, slightly swollen 

 in middle, with a long articulated terminal spine. Harpes narrowly elliptical, 

 concave, inner margin thickened and revolute, tip pointed and recurved. 

 Harpagones with a slender columnar base bearing a short seta on inner side and 

 a long, very narrow, articulated terminal filament with a pointed tip. Unci 

 approximate, revolute, forming a large basal cone. Basal appendages small, 

 rather remote, bearing three stout spines at tip. 



Larva, Stage IV (plate 125, fig. 435). Head rounded, narrowed before 

 eyes, a slight notch at insertion of antennae, front margin arcuate. Antennae 

 cylindrical, slender, uniform, sparsely spined ; a single hair at middle ; four 

 spines of irregular length at tip and a digit on a pedestal. Upper pair of dorsal 

 head-hairs single, lower pair double, ante-antennal tuft three-haired. Mental 

 plate rounded triangular ; teeth slightly radial, uniform, sixteen on each side, the 

 basal one detached and smaller. Mandible quadrangular, rather short, slightly 

 spined outwardly near base; two filaments near tip; an outer row of cilia; 

 twelve filaments on outer edge; dentition of four teeth on a process, the first 

 and fourth longer; two filaments at base, short teeth without, a broad plate and 

 four hairs within; process below furcate, with patches of hair; basal angle 

 moderate ; three stout hairs within ; a row of five hairs at base. Maxilla hemi- 

 spherical, narrowed without, divided by a suture ; inner half sparsely hairy, a 

 tuft of hairs at tip ; outer half very sparsely hairy, two large filaments at the 

 suture near the tip; palpus short and stout, with four small digits, of which 

 one is a mere rudiment. Thorax rounded, wider than long; hairs moderate. 



