Hemipenthes scylla (Osten Sacken)

Ávalos-Hernández, Omar, 2009, A review of the North American species of Hemipenthes Loew, 1869 (Diptera: Bombyliidae), Zootaxa 2074, pp. 1-49 : 35-37

18. Hemipenthes scylla (Osten Sacken)

(Figs. 20, 67–68)

Anthrax scylla Osten Sacken, 1887: 132 .

Argyramoeba succincta Coquillett, 1894a: 96 .

Villa (Hemipenthes) scylla (Osten Sacken) : Painter & Painter, 1965: 436. Villa (Hemipenthes) succincta (Coquillett) : Painter & Painter, 1965: 436. Hemipenthes scylla (Osten Sacken) : Hull, 1973: 386.

Hemipenthes succincta (Coquillett) : Painter et al., 1978: 49.

Lectotype of Anthrax scylla designated by Painter & Painter (1962: 123) in BMNH. Holotype of Argyromoeba succincta in USNM.

Diagnosis: Cell r1 with basal half infuscated and a color spot at tip; cell r2+3 infuscated just at base; cells bm and dm hyaline or infuscated just at tip.

Description: Male. Body length: 6–11 mm; wing length: 6–10 mm. Head: Eyes separated by a little more than width of ocellar triangle. Front black pilose, black and fulvous tomentose. Face black, rounded, with black hairs and fulvous tomentum. Scape brown, swollen on inner apical margin, with black hairs, twice as long as pedicel; pedicel brown, twice as wide as long, with black hairs; flagellomere black, 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 or cinereous with black hairs. Occiput with short black hairs and yellowish scales.

Thorax: Mesonotum anterior margin yellowish pilose; lateral margin entirely white pilose; tomentum on disc yellowish, long, hairlike, not dense, more abundant on anterior margin and region before scutellum; bristles black. Mesopleuron yellowish pilose with black hairs mixed in on proepisternum, anepisternum, and sometimes katatergite, tomentum on katepisternum yellowish. Proepimeron with black and yellowish hairs. Mid coxa with black hairs, tomentum on all coxae hairlike, yellow. Legs yellow, tarsi black, femora black pilose, yellow tomentose, femora with some black scales; fore tibia without bristles, mid and hind tibiae with black bristles. Halter steam brow, knob yellow. Scutellum brown, not pilose, yellow tomentose, paler along posterior margin, a spot of black tomentum in middle at base; bristles black. Black setulae on basicosta. Cells c, sc, br, and bm entirely infuscated (Fig. 20); cell r1 with two basal thirds infuscated, with a spot at tip; cell cup with basal half infuscated; cells r2+3, r5 and a infuscated just at base; r-m crossvein at basal third of cell dm; no crossvein between R4 and R2+3; cell r5 slightly narrowed at wing margin; first section of vein CuA1 one and a half the long of r-m crossvein, second section twice the long of r-m crossvein, third section two and a half the long of the first two sections combined; cell a as wide as cell cup; alula poorly developed.

Abdomen: Abdominal dorsum white pilose, more dense in tergites five to seven; black tomentum overall, some white scales scattered on tergites fifth to seventh; sides of abdomen with first and basal half of second tergite whitish pilose with a tuft of black hairs on first tergite, rest with abundant black pile. Venter white pilose, yellowish tomentose. Genitalia brown with black and yellow 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. 67 ) 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. 68 ), lateral margins narrowed at middle, with scattered spines all along; aedeagus broad at base narrowed at apex, not swollen dorsally; gonopore terminal.

Female. Not studied.

Distribution: Mexico (Aguascalientes, Chiapas, Distrito Federal, Durango, Guanajuato, Guerrero, Hidalgo, Jalisco, Michoacán, Morelos, Nuevo León, Oaxaca, Puebla, Queretaro, San Luis Potosí, Sonora, Zacatecas), USA (Arizona, Texas).

Specimens examined: Mexico. Michoacán: 12 mi W Morelia, 24-VIII-1968, R. H. and E. M. Painter (1 male; USNM). Morelos: Quilamula, 8-II-2004, O. Ávalos y M. López (1 male genitalia; MZFC); 15 mi E Cuernavaca, 17-IX-1963, R. H. and E. M. Painter (1 male; USNM); 13 mi E Cuernavaca Lobo Cn., 15- VIII- 1962, R. H. and E. M. Painter (1 male; USNM); 11 mi E Cuernavaca Lobo Cn., 15-VII-1962, R. H. and E. M. Painter (1 male; USNM); 12 mi E Cuernavaca Lobo Cn., 13-IV-1966, R. H. and E. M. Painter (1 male; USNM).

Remarks: Only males have been collected from Hemipenthes scylla . Externally it is distinguished by the reduced pigmentation of wing, limited to the base and anterior margin of wing, like in H. albus , H. lepidota , H. translucens , and H. webberi , but in contrast with these species H. scylla has characteristic pigmentation in cell r1. Hemipenthes scylla is a common species and has been reported as territorial ( Ávalos-Hernández, 2007). It is distributed throughout Mexico having its most northern limit in Arizona and Texas.

Figures

FIGURES 67 – 68. Hemipenthes scylla male terminalia. 67, lateral view; 68, ventral view.