Hemipenthes bigradata (Loew)

Ávalos-Hernández, Omar, 2009, A review of the North American species of Hemipenthes Loew, 1869 (Diptera: Bombyliidae), Zootaxa 2074, pp. 1-49 : 9-11

2. Hemipenthes bigradata (Loew)

(Figs. 2, 29–30)

Anthrax bigradata Loew, 1869: 23

Hemipenthes bigradata (Loew) : Hull, 1973: 385.

Holotype in MZC

Diagnosis: Mesopleuron black and yellow pilose; cell a with at least basal half infuscated, color not reaching hind margin; first and fourth abdominal tergites with a stripe of white scales.

Description: Male. Body length: 5–10 mm; wing length: 4–9 mm. Head: Eyes separated by one and a half width of ocellar triangle. Front black pilose, yellowish tomentose. Face brown, rounded, with black hairs and yellowish tomentum. Scape brown, swollen on inner apical margin, with black hairs, twice as long as pedicel; pedicel brown, twice as wide as long, short black hairs on the base; flagellomere brown on the base, testaceous on apex, longer than scape and pedicel combined; base subconical, tapering to styliform apical two-thirds; stylus minute, terminal. Proboscis short, not projecting beyond oral margin. Palpi brown with black hairs. Occiput with short black and yellow hairs and yellowish scales.

Thorax: Mesonotum anterior margin yellowish pilose; lateral margin white and yellowish pilose; tomentum on disc yellowish, short, hairlike, not dense; bristles black. Mesopleuron black pilose with yellowish hairs mixed in on proepisternum and anepisternum, katatergite with yellowish hairs, some black hairs mixed in, tomentum on katepisternum black with some yellowish scales present, hairlike, not dense. Proepimeron yellowish pilose, with a few black hairs present. Mid coxa with black hairs, tomentum on all coxae hairlike, yellow. Legs fulvous, femora black pilose, tomentum on fore and mid femora black, hind femur yellowish tomentose, black scales present on anterior surface; fore tibia with a single row of black bristles on postero-ventral surface; bristles black. Halter steam pale yellow or brown, knob yellow to white. Scutellum brown, not pilose, and pale yellow tomentose, not dense; bristles black. Black setulae on basicosta. Cells c, sc, br, and bm entirely infuscated (Fig. 2); cells r1, cup and a with two basal thirds infuscated; cell dm with basal half or less infuscated; cells r2+3, r5, cua1 and m2 infuscated just at base; color in cell a not reaching hind margin of wing; cell dm infuscated behind r-m crossvein; r-m crossvein behind middle of cell dm; no crossvein between R4 and R2+3; cell r5 slightly narrowed at wing margin; first section of vein CuA1 twice and a half the long of r-m crossvein, second section half the long of r-m crossvein, third section twice the long of first two sections combined; cell a slightly wider than cell cup; alula slightly developed.

Abdomen: Abdominal dorsum black pilose, some white hairs on apical half of first tergite; black tomentum overall except a broad crossband of white tomentum on apical half of first tergite and on all fourth tergite, tergites six and seven with scattered white scales; sides of abdomen with first and basal half of second tergites whitish pilose, rest black pilose. Venter black pilose, whitish tomentose. Genitalia brown with black hairs. Epandrium in lateral view, rectangular, lower margin concave in middle, basal corner narrowed; gonocoxite narrow, basal half enlarged; gonostylus small, hooked apically; epiphallus in lateral view narrow ( Fig. 29 ) slightly curved, cap-shaped, apex swollen, rounded; with a ventral extension broad at base with apex acuminate, portion of the epiphallus behind ventral extension longer than aedeagus; epiphallus in ventral view broad ( Fig. 30 ), lateral margins narrowed at both sides at middle, with scattered spines all along; aedeagus broad at base narrowed at apex, not swollen dorsally; gonopore terminal.

Female. Nearly identical to male. Eyes separated by twice width of ocellar triangle.

Distribution: Mexico (Distrito Federal, Guanajuato, Guerrero, México, Puebla, Sonora), USA (Arizona, California, New Mexico, Texas, Washington).

Specimens examined: USA. California: Ribbonwood San Jacinto Mts., 20-V-1939, B. Brookman (1 female; USNM); Los Angeles (2 females; USNM), S. Bernardino Co., May (1 female; USNM). New Mexico: Koehler, N. R. Walton (1 male genitalia; USNM). Washington: Pullman, 16-VI-1912 (1 male; USNM).

Remarks: Hemipenthes bigradata is similar to H. chimaera but can be distinguished by the presence of yellow and black pile on mesopleuron. The genitalia of both species are clearly different, mainly by the presence of a ventral extension in H. bigradata genitalia. The examined specimens are only from USA localities but this species has also been reported from Mexico ( Evenhuis & Greathead, 1999).

Figures

FIGURES 29 – 30. Hemipenthes bigradata male terminalia. 29, lateral view; 30, ventral view.