MEGAEHINU8 StrPEEBUS 935 



through violet and purple to a brilliant coppery-bronze on sixth and seventh 

 segments, eighth segment deep blue, purple scaled in middle; apical half of 

 lateral margin of sixth segment and lateral margins of seventh and eighth 

 segments with a long fringe of brilliant red ciliate scales of silky luster; the 

 usual lateral hairs of abdomen present on the preceding segments but sparse 

 and very delicate ; claspers purple scaled, with a few coarse black hairs ; venter 

 golden scaled at sides, a median longitudinal stripe steel blue. Wiags narrow, 

 with a smoky tinge along costal area ; basal cross-vein oblique, reaching fourth 

 vein just behind anterior cross-vein. Halteres stout at base, the knobs bearing 

 silvery scales. Legs dark blue and purple, the femora and hind tibise brassy 

 beneath. Claw formula, 1.0-1.0-0.0. 



Length : Body 7 to 8 mm. ; wing 4.5 mm. 



Genitalia (plate 37, fig. 347) : Side-pieces over twice as long as wide, much 

 tapered to tips, conically rounded ; a low conical basal lobe bearing setae similar 

 to those on side-pieces. Clasp-filament long and slender, as long as side-piece, 

 smooth, with a long articulated terminal spine. Harpes large, concave, margin 

 revolute, tips bent outward and pointed. Unci long, tapered to sharp points, 

 tips shortly recurved, basal part dentate within. Basal appendages small, 

 rounded, rather approximate, with a deep emargination between, each bearing 

 four setae. 



Larva, Stage IV (plate 137, fig. 442). — Head subquadrate, longer than wide, 

 sides nearly straight, insertion of antennge rather prominent; front margin 

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

 lobe. Antennae cylindrical, slender, rather long, smooth ; three hairs separately 

 at outer third ; a terminal hair and two digits on pedicels. Mental plate broadly 

 trilobed and with irregular teeth ; central portion with a median tooth and four 

 on each side, lateral portions of five teeth, roimdedly prominent. Mandible 

 rounded-quadrangular, small, but with very large dentition; two numerously 

 divided filaments before tip ; a row of cilia from a collar overlapping the denti- 

 tion, which consists of five large teeth, third shorter than the others ; a slight 

 irregularity below; a row of long basal hairs. Maxilla quadrate, inner third 

 roundedly produced; outer margin with long spines, inner ones on the pro- 

 longation curved outwardly; a long spine from a tubercle in middle of outer 

 portion; palpus long, with five minute apical digits. Thorax rounded, about 

 as wide as long; lateral hairs short, very stout, the heaviest ones spinulose. 

 Abdomen stout, the segments angled at the sides, anterior ones narrow and 

 transverse ; hairs abundant but not long. Skin pale ; chitinized parts yellow. 

 Eighth segment with a large plate on the sides. Air-tube rather slender, slightly 

 tapered, over four times as long as wide; a single tuft at basal fifth. Anal 

 segment as long as wide, ringed by the plate ; dorsal tufts of five long hairs on 

 each side ; ventral brush well developed, of coarse ciliate hairs, confined to barred 

 area ; anal gills very short. 



The larvse live in the water held by the leaf-bases of epiphytic Bromeliacese 

 and feed upon the other mosquito larvse in such situations. Mr. Knab found 

 them associated with Wyeomyia dbebela, Gulex rejector, and Culex stenolepis, 

 the Wyeomyia much in the minority, and again with larvse of Gulex and Psy- 

 chodidae, the Wyeomyia being absent, probably all devoured by the Megarhinus. 

 Mr, Busck found them feeding upon Wyeomyia circumcincta, while Wyeomyia 

 scotvnomus and Gulex jenningsi were also present. The adults are diurnal and 

 feed upon the nectar of flowers. Mr. Busck saw specimens flying in the tree- 

 tops while he was collecting the larvae, and Dr. Wise has captured specimens on 

 the wing at 4 p. m. Mr. Urich has found both sexes feeding upon the nectar of 

 the flowers of Eupatorium odoratum during the middle of the day. 



Forested regions of tropical America from southern Mexico to Guiana and 

 probably Brazil; Cuba. 



