H^MAGOGUS EQUINUS 873 



bristles over roots of wings short, black. Scutellum trilobate, middle lobe 

 broad ; clothed with broad, flat, metallic green and blue scales, each lobe with a 

 group of black bristles. Postnotura elliptical, prominent, black, slightly prui- 

 nose, nude. Pleural and coxae blackish, nearly solidly clothed with flat silvery- 

 white scales; setse minute, dark. 



Abdomen subcylindrical, sixth and seventh segments apically enlarged be- 

 neath, eighth segment tapered posteriorly; dorsal vestiture of metallic, shining 

 blue scales, the segments beyond the second with a basal silvery-white patch 

 becoming bands on sixth and seventh segments, a series of large, lateral, tri- 

 angular, segmentary, basal silvery- white spots ; first segment dark metallic blue 

 scaled on the disk, silvery-white at the sides, with fine dark hairs ; venter dark 

 metallic blue scaled, with silvery segmentary basal bands. 



Wings moderate, hyaline; petiole of second marginal cell somewhat longer 

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

 distant more than its own length from anterior cross-vein; scales brownish- 

 black, on the costa black with a blue reflection, the outstanding ones narrowly 

 ligulate, denser and broader on the second vein. Halteres whitish, with the 

 knobs black. 



Legs rather long and slender; vestiture black with dark violet-blue reflec- 

 tion; trochanters silvery-whitish; hind femora silvery-white beneath and on 

 outer side to near apex; knees of middle and hind legs silvery-white scaled. 

 Claw formula, 1.1-1.1-0.0. 



Length : Body about 4 mm. ; wing 3 mm. 



Male. Proboscis nearly straight, long and slender, black scaled. Palpi 

 about three-fourths as long as the proboscis, slender, uniform, the last two 

 joints with a few stiff bristles; vestiture dark violet-blue. Antenna plumose, 

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

 broadly ringed with black at insertions of hair-whorls ; hairs of whorls long, fine, 

 black, and rather dense. Prothoracic lobes less closely approximate dorsally 

 than in the female. Coloration similar to the female. Abdomen elongate, sub- 

 cylindrical, slightly enlarged apically, dorsally with all but the second segment 

 with basal silvery bands; lateral ciliation short, rather sparse, fine, blackish. 

 Wings narrower than in the female, the stems of the fork-cells longer ; vesti- 

 ture sparse. Claw formula, 1.1-1.1-0.0. 



Length : Body about 4 mm. ; wing 3 mm. 



Genitalia (plate 23, fig. 162) : Side-pieces about twice as long as wide, 

 rounded at tip ; basal lobe represented by a small rounded protuberance at base, 

 densely setose ; a row of large outstanding scales on inner aspect of side-piece. 

 Clasp-filament short and slender, with a long articulated terminal spine. Harpes 

 broad, wide at base, margin narrowly recurved, tips rounded. Harpagones with 

 a thick, bent columnar base, pilose, terminated at the tip by a thin, broad, leaf- 

 like twisted plate. Unci contiguous, revolute, forming a small basal cone. No 

 basal appendages. 



Larva, Stage IV. Head rounded, widest through the eyes, a slight notch 

 at insertion of antennae, front margin broadly rounded. Antennae moderate, 

 slender, very sparsely spined, a single hair near middle; four irregular 

 apical spines and a long digit with a small subbasal branch. Both pairs of 

 dorsal head-hairs single, ante-antennal tufts triple. Mental plate triangular, 

 with a stout central tooth and eight on each side, the two basal ones remote and 

 angular, the outer one small and very remote. Mandible quadrangular, a few 

 spines at base; two filaments from a notch before tip; an outer row of cilia 

 from a collar; a row of long filaments on outer margin ; dentition of a curved 

 tooth on a process with three little ones on the lower declivity and a larger one 

 below; a smooth filament and row of feathered hairs within; process below 

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