Heteromydas Hardy

J. Wilcox & N. Papavero, 1971, The American Genera of Mydidae (Diptera), with the Description of three new Genera and two new Species, Arquivos de Zoologia 21 (2), pp. 41-119 : 86-88

Genus Heteromydas Hardy

Heteromydas Hardy, 1944: 227 , figs. 3a-f. Type-species, bicolor Hardy (orig. des.).

Head in anterior view one and four-tenths times as broad as high; face at antennae nearly one-half width of head. Oral margin at about one-third distance from lower eye margin to antennae; gibbosity with a central vertical groove. Proboscis similar to Messiasia J the labella as long as oral cavity; palpi slender and one-half the length of the oral cavity or more. Antennal segment 1 cylindrical, about one and one-half times as long as broad; 2 one-half length of 1 and slightly wider than long; 3 long and slender, about three times as long as 1-2; club about three-fourths length of 3, fusiform and at middle about one-third as wide as long (Fig. 16).

Mesonotum with lateral margins and dorsocentral stripes at times pollinose, including the central stripe and intermediate area anteriorly; hairs short. Scutellum with sparse long hairs on posterior margin. Postscutellum smooth, lateral slopes pilose. Pleura pilose on episternum-1, posterior margin of mesopleura, pteropleura and metasternum.

Abdominal tergite-1a slightly rounded, bare; 1-p with quite dense, short, erect, pilosity; remaining segments with sparse recumbent hairs; bullae slender and about five times as long as broad. Sternites with sparse semi-recumbent hairs becoming numerous on 7-8; 0' 8 nearly as long as 7; ~ segment 8 with dense erect hairs. Female with terminal circlet of strong spines. Male genitalia (Figs. 82-84): hypandrium free, small, bowl-shaped in lateral view, coalesced with the basal portions of the basistyli for a short distance; gonopods with apical processes slender, pointed to the interior of the genitalia; aedeagus long and very thick; anal lamellae and cerci slightly longer than aedeagus, cerci coalesced basally; epandrial halves triangular, free; postero-lateral margins of epandrium prolonged into a pair of elongated lobes; cerci and epandrium with moderately long hairs. The male genitalia of Heteromydas was also described and figured by Hardy [1944: figs. 3C (lateral view), 3E (ventral view), 3F (dorsal view) J.

Hind trochanters with 2-5 short strong spines. Fore and middle legs slender. Hind femora moderately swollen, a about six and ~ about seven, times as long as wide; venter with 16 spines slightly tuberculate; hairs recumbent, short and erect on dorsum. Hind tibiae with a ventral keel, apical spur slightly longer than width of metatarsus and with a basal bristle. Hind metatarsus about five times as long as broad and as long or longer than segments 2-4.

Alulae with a dense fringe of squamose hairs. Wings about three and one-half times as long as broad; second submarginal cell open; posterior crossvein present; axillary lobe nearly as broad as long; ambient vein complete.

Length, 22-29 mm.

Geographic range: U. S.A. (California), Mexico (Baja California).

Papavero & Wilcox (1968) placed Mydas chrysites Osten Sacken in Heteromydas Hardy , based on the identification and figures of Seguy (1928). This species was described from Northern Sonora (Mexico) and Johnson (1926) identified a specimen from Southern Arizona; Dr. Howard Evans, MCZ, confirmed that it belonged in Mydas Fabricius. The type was examined by the junior author in the BMNH, and proved to be a real Mydas . Specimens of both sexes have since been examined (from Southern Arizona) and they agree so well with the description, that it appears that Seguy (1928) was incorrect in his identification; he gave no locality for his specimens, but they probably represent an undescribed species of Heteromudas from Baja California.