Geron nigripes Painter
Creators: name: Hall, Jack C.
name: Evenhuis, Neal L.
Publisher: name: Zenodo
Year: 2003
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Bombyliidae
Geron
Geron nigripes

description: Geron nigripes Painter
Geron nigripes Painter, 1932: 152. Painter & Painter 1965: 423. Cole & Schlinger, 1969: 234. Hull 1973: 206. Evenhuis 1983: 482. Poole & Gentili 1996: 71. Evenhuis & Greathead 1999: 46. Geron winburni Painter, 1932: 157. Priddy 1939: 47. Painter & Painter 1965: 423. Cole & Schlinger 1969: 234. Hull 1973: 206. Tabet 1974: 21. Evenhuis 1983: 493. Tabet & Hall 1984: 33. Poole & Gentili 1996: 71.
Description. Male. Head. Front silvery tomentose, hair wanting; antenna black; scape with white hairs, a few black hairs apically; pedicel with short black hair; first flagellomere narrow, tapering from base to acuminate apex; antennal ratio: 9:4:21; face cinereous pollinose, white pilose, bare medially, tomentum silvery, restricted to side at eye margin; oral margin pale yellowish white; proboscis projects beyond oral margin for a distance two times head height; gena white pilose and tomentose; occiput white pilose and tomentose on lower half, upper half, or less, pale yellow pilose, tomentum wanting; ocellar tubercle with black hair.
Thorax. Mesonotum dull black, side narrowly cinereous pollinose; median longitudinal stripe not evident; notum with pale yellow hair, shorter black hair medially on posterior half, tomentum wanting; pleura white pilose and tomentose; legs black, white pilose and tomentose, hind femur with yellowish scales on dorsal surface; halter with stem brown; knob yellowish; scutellum yellow pilose, tomentum wanting.
Wing (Fig. 27). Hyaline; venation normal; crossvein r­m slightly beyond middle of cell dm; crossvein m­cu slightly sinuous; basicosta with white hair.
Abdomen. Dorsum white to pale yellow pilose, golden yellow tomentose, tomentum not dense; side and venter white pilose and tomentose; tergites with lateral margins black; sternites with posterior margins black.
Genitalia (Fig. 45) with gonocoxa in ventral view flat, without depressions or ridges, in lateral view narrowly rectangular, lower margin with a long projection near apex; gonostylus narrow, rounded apically; lateral ramus narrow, slightly curved, shorter than gonostylus; dorsolateral ramus short, stub­like.
Female. As in male except as follows: Head. Eyes at vertex separated by slightly less than two times width of ocellar tubercle; front with yellow hair and tomentum, silverwhite tomentum next to eye margin and above bases of antennae; occiput with golden yellow hair and tomentum. Thorax. Mesonotum with golden yellow pile and tomentum, the latter abundant; median longitudinal cinereous stripe narrow, reaches transverse suture; scutellum with abundant golden yellow tomentum; fore tarsi with palynophilic setae.
Abdomen. Dorsum yellow pilose and golden yellow tomentose. Genitalia with posterior projection of tergite VIII rounded, black; vaginal furca (Fig. 15) simple, upper half narrowly U­shaped; lower half with arms straight, lanceolate, slightly twisted, broad, apically slightly swollen.
Types. Holotype male and allotype of G. nigripes (Monrovia Canyon, California, 3.viii.1930, T.F. Winburn & R.H. Painter) in USNM (No. 44868). Holotype male and allotype of G. winburni (Los Banos, California, 28.vii1930, T.F. Winburn) in USNM (No. 101430). The holotype of G. nigripes is badly abraded, the left third antennal segment, fore and hind legs, and wings are missing. The holotype of G. winburni is in good condition, only the right middle leg is missing. The genitalia of both species have been dissected and placed in microvials attached to the pins. Types studied by senior author.
Material Examined. United States. California. Fresno County: 3, Millwood, 23.viii.1952 (J.C. Hall) (UCR). Inyo County: 1, Westgard Pass, 17.viii.1958 (R.H. & E.M. Painter) (USNM). Lake County: 1, Hopland Grade, 29.vi.1959 (S.M. Fidel) (UCR). Los Angeles County: 22, Tanbark Flats, 14.vii.1956, 10.vii.1950, 24.vi.1950 (H.M. Stebbins, K.G. Whitesell) (UCR); 1, San Rafael Hills, 7.ix.1956 (C.L. Hogue) (UCR). Mendecino County: 1, Hopland, 15.viii.1954 (S.M. Fidel) (UCR). Monterey County: 2, Arroyo Seco, 15.viii.1964 (G.R. Ballmer) (UCR). Napa County: 1, 11 mi. E Monticello, 12.viii.1956 (S.M. Fidel) (UCR). Nevada County: 1, Grass Valley, 5.vii.1956 (J. Powell) (UCR). San Bernardino County: 18, Forest Falls, 22.vi.1981 (J.C. Hall) (UCR); 1, Mill creek Canyon, 23.vii.1981 (J.C. Hall) (UCR); 1, Mountain Home, 12.ix.1953 (E.I. Schlinger) (UCR); 28, Oak Glen, 5–15.viii.1985, Malaise trap (R.E. Wagner) (UCR). Texas. Cameron County: 1, 22 mi. N. Raymondville, 26.iv.1966 (R.H. & E.M. Painter) (USNM).
Variation. The pile on the body varies from white to golden yellow and the tomentum varies from yellow to golden yellow. Some specimens have the hair on the basal antennal segments and the ocellar tubercle white instead of black. The mid and hind tibiae are often brownish. In the female vaginal furca there often is a small translucent swelling on the arms of the lower half.
Discussion. The long projection on the venter of the gonocoxa is a reliable means of recognizing G. nigripes. This projection is longer and more easily seen, even in the rosette condition, than in the other species, which possess a projection. A comparison of the male genitalia of both G. nigripes and G. winburni supports the synonymy of the two species.
Biology. Nothing is known of the immatures. Adults have been taken at flowers of Eriogonum fasciculatum, Achillea sp., and Tetradymia canescens.
Distribution. United States (California, Texas).
description: Published as part of Hall, Jack C. & Evenhuis, Neal L., 2003, Review of the subgenus Geron (Geron) Meigen in the Nearctic Region (Diptera: Bombyliidae: Toxophorinae), pp. 1-72 in Zootaxa 181 on pages 41-43, DOI: 10.5281/zenodo.156842