938 MOSQUITOES OF NORTH AMERICA 



Evidently closely related to Megarhinus violaceus Wiedemann, described from 

 the State of Bahia, Brazil, but does not agree with the description of that species in 

 several details. In that species the lateral tufts of the sixth segment are said to be 

 golden and there is no mention of the abdominal lateral silvery spots, so conspicuous 

 in the specimen before me. 

 Desceiption of Female and Larva of Megabhinus violaceus : 



Female. Proboscis curved, tapering gradually to tip ; vestiture bronzy black. 

 Palpi long, over three-fourths the length of the proboscis ; terminal joint minute, 

 penultimate joint about half the length of long joint, with a few scattered short 

 bristles and terminally with a number of very stout bristles, long joint with a 

 constriction considerably before the middle; vestiture of brilliant violet and 

 blue scales, beneath and dorsally at the constriction of the long joint golden 

 scaled. Antennae filiform, delicate, the joints subequal, the second longer, 

 slightly thicker and with a dorsal crest of small raised scales ; hairs of whorls 

 moderate, sparse, black ; tori small, black, with silvery gray pruinosity. Clypeus 

 not prominent, transverse, hardly produced at middle, black, silvery gray prui- 

 nose. Occiput covered with appressed broad metallic blue scales with violet 

 and green iridescence; cheeks dull silvery scaled. 



Prothoracic lobes lateral, large and prominent, covered with brilliant metallic 

 blue scales. Mesonotum covered with dark olivaceous bro^vn scales with blue, 

 green and purple reflections, a patch of brilliant blue scales over the roots of 

 wings; bristles over roots of wings black. Scutellum covered with bright 

 metallic blue scales and with coarse brown marginal bristles. Postnotum ocher 

 yellow, shining, nude. Pleurae and coxae dull brown, densely clothed with silvery 

 white scales. 



Abdomen subcylindrical, depressed outwardly, truncate at tip; dorsal vesti- 

 ture of deep metallic blue scales, on basal segments with a slight greenish tinge, 

 numerous scattered brilliant violet-red scales, particularly on apical margins 

 of segments and on distal ones upon the disk, a series of large subquadrate 

 yellowish-silvery spots laterally at bases of second to seventh segments, the first 

 segment broadly silvery at the sides ; a tuft of pale yellowish hair-scales at the 

 sides of the sixth segment and involving its distal half, a lateral tuft of black 

 hair-scales involving distal two-thirds of seventh and base of eighth segments ; 

 venter pale yellowish-silvery scaled, with a median dark line. 



Wings narrow; second marginal cell very small, second posterior cell about 

 one-third the length of its petiole ; basal cross-vein oblique, more than its own 

 length before anterior cross-vein ; scales of veins small, subtruncate, brown with 

 violet luster. Halteres with pale stems and black knobs. 



Legs rather long, dark metallic blue scaled with a violet reflection, darker 

 distally ; femora broadly silvery white scaled beneath nearly to apices. Claw 

 formula, 0.0-0.0-0.0. 



Length : Body about 8 mm. ; wing 5.5 mm. 



Male. We have seen no specimen of this sex. It differs in the usual sexual 

 characters and the coloration appears to be much like that of the female. The 

 caudal tuft is said to be golden yellow and black, the yellow hair-scales occupying 

 the sides of the sixth segment and the apical margin of the eighth. 



Larva, Stage IV. Head subquadrate, about as long as wide, the posterior 

 angles rounded, insertion of antennas rather prominent; front margin deeply 

 emarginate at middle, produced on each side of it into a large prominent lobe. 

 Mouth-l)rushcs inserted beneath apices of frontal lobes, each consisting of ten 

 stout curved lamelliform blades with hooked tips. Antennae very slender and 

 rather long, subcylindrical, slightly thickened at base. Skin of body during life 

 showing iridescent colors and spotted with red and green; chitinized parts 

 yellow. Air-tube rather slender, slightly tapered, over four times as long as 

 basal width ; a single pair of tufts at basal sixth. Anal segment about as long 



