36 MOSQUITOES OF NOKTH AMEKICA 



ally to the clypeus. Occiput clothed with flat, shining metallic green, violet, and 

 blue scales, two brown setae at vertex; cheeks silvery. 



Prothoracic lobes large, approximate dorsally, clothed with pale metallic-blue 

 scales, bearing a dense row of black bristles. Mesonotum blackish, clothed with 

 flat metallic blue and green iridescent scales. Scutellum trilobate, densely 

 covered with scales similar to those of the mesonotum, each lobe with a small 

 tuft of brown bristles. Postnotum elliptical, prominent, dark brown, with a 

 rounded median carina, a tuft of about ten large bristles posteriorly ; without 

 scales. Pleurae dark brown, coxae luteous, clothed with elliptical, flat silvery- 

 white scales ; an irregular patch of dark-brown scales behind the prothoracic lobe. 



Abdomen subcyKndrical, compressed, truncate at tip, which bears a tuft of 

 long black hairs ; dorsal vestiture black, with metallic blue and violet reflection ; 

 first segment more brilliantly colored; venter yellowish silvery-white, the colors 

 separated on the sides in a sharp, strongly undulating line. 



Wings rather narrow, hyaline, iridescent ; petiole of second marginal cell one- 

 third as long as its cell, that of second posterior cell shorter than its cell ; cross- 

 veins nearly incident; scales of veins black, with bronzy and blue reflection, 

 elliptical, mostly obliquely subtruncate, those on forks of second vein slightly 

 larger and denser. Halteres blackish, except at the base. 



Legs moderate, vestiture black with a blue and violaceous reflection, slightly 

 roughened beneath at tips of hind tibiae and base of first tarsal joiiit; femora and 

 tibiae and first tarsal joint of hind legs with a strong brassy luster beneath, the 

 other tibiae and tarsi with cupreous luster. Claw formula, 0.0-0.0-0.0. 



Length : Body about 4 mm. ; wiag 3.5 mm. 



Male. — Entirely similar to the female, claws of fore feet slightly unequal, 

 abdomen enlarged at tip and truncate, tuft of black hairs divided. 



Genitalia (plate 3, fig. 6) : Side-pieces over twice as long as wide, tips conic- 

 ally tapered, a small, scarcely separated lobe at base bearing two stout setae 

 and a number of fine hairs. Clasp-filament with a large, inflated, distorted 

 branch, a slender inward branch at basal third long and recurved, a small branch 

 at outer third, curved, with a bent divided tip, apex slightly inflated, bearing 

 a series of spines at tip, outer aspect pilose, a large inward inflated projection at 

 outer third bearing a long marginal row of coarse teeth and a shorter flner sub- 

 marginal row. Harpes flat, tapering outwardly, inner margin revolute, tip 

 dentate. Harpagones and unci forming basal cones. Basal appendages repre- 

 sented by two groups of five spines each, remote from one another. 



Larva, Stage IV (plate 86, fig. 371). — Head rounded in front, sides oblique, 

 posterior angles prominent, rounded ; occipital foramen visible near the sides in 

 dorsal aspect; antennae moderate, uniform, a single small seta at outer fourth; 

 head-hairs single, ante-antennal tuft multiple, fiiteral comb of eighth segment 

 of about eleven scales in a single irregular row. Air-tube slightly tapered, uni- 

 form, about three times as long as wide, roughened with short, closely set 

 denticles ; a small hair on dorsal aspect near tip, four on ventral aspect, and a 

 longer hair laterally about the middle; terminal hooks moderate. Anal seg- 

 ment longer than wide, with a rather large dorsal plate; dorsal tuft of five hairs 

 on each side, lateral hair single, arising from the angle of the plate ; subventral 

 hair long, single, arising from a small, independent plate. Anal gills about 

 twice as long as the segment, stout, tapering to tip, slightly flexuous. A pair 

 of toothed dorsal hooks on seventh abdominal segment. 



The life history and habits of Sahethinus identicus are identical with those of 

 Sdbethinus undosus, the larvae in several instances occurring associated with 

 larvae of that species. Mr. Busck says : " The large, fat, milky-white larva is 

 strongly segmented and has a short tube." 



