Geron monticola Hall & Evenhuis

Hall, Jack C. & Evenhuis, Neal L., 2003, Review of the subgenus Geron (Geron) Meigen in the Nearctic Region (Diptera: Bombyliidae: Toxophorinae), Zootaxa 181, pp. 1-72 : 37-40

Geron monticola Hall & Evenhuis , sp. nov.

Description. Male. Head. Frontal triangle silver­white tomentose, hair wanting; antenna black; scape with white hair; pedicel with short black hair; first flagellomere evenly tapering from base to acuminate apex; antennal ratio: 7:3:17; face white pilose, bare medially; silver­white tomentum opposite antennal base; oral margin pale; proboscis projects beyond oral margin for a distance twice head height; gena white pilose and tomentose; occiput white pilose, white tomentum on lower half, scattered; ocellar tubercle with short black hair.

Thorax. Mesonotum velvety black, lateral and anterior margins cinereous to brownish pollinose; median longitudinal stripe vague, brownish, not reaching transverse suture; notum with white pile, shorter black hair medially behind transverse suture, tomentum wanting except for a few golden yellow scales near posterior margin; pleura white pilose and tomentose; legs black with white hair and scales; halter with stem and knob white; scutellum white pilose, tomentum wanting.

Wing. Hyaline; venation normal; crossvein r­m slightly beyond middle of cell dm; crossvein m­cu slightly sinuous; basicosta with white hair.

Abdomen. Dorsum white pilose, pale yellow to yellow tomentose; side and venter pilose and tomentose; tergites with lateral margins black; sternites with posterior margins narrowly pale.

Genitalia ( Fig. 43 ) with gonocoxa in ventral view flat, without depressions or ridges, in lateral view narrow, elongate, lower margin with a small, pointed projection; gonostylus short, three times longer than high, rounded apically; lateral ramus narrow, slightly curved, coextensive with gonostylus; dorsolateral ramus long, broad, slightly shorter than lateral ramus.

Female. As in male except as follows: Head. Eyes separated at vertex by one and onehalf times width of ocellar tubercle; front with white hair, tomentum golden yellow medially, white laterally and above antennal base; antennal scape and pedicel with white hair; upper half of occiput with golden yellow tomentum. Thorax. Mesonotum with golden yellow tomentum; median longitudinal stripe brownish, short, not reaching transverse suture; scutellum with white to pale yellow hair and golden yellow tomentum. Abdomen. Dorsum golden yellow tomentose. Genitalia with posterior projection of tergite VIII black; vaginal furca ( Fig. 13 ) simple, narrow, upper half narrowly U­shaped; lower half with arms slightly bowed, narrow, apex with small tooth.

Types. Holotype male and allotype (Summit Valley, San Bernardino County, California, 26. vii.1978, J.C. Hall). Paratypes. California. 64, topotypic, collected with types (J.C. Hall, J. LaSalle, G. Gordh). Holotype and allotype deposited in USNM. Paratypes deposited in USNM and UCR.

Variation. In both sexes the hair on the second antennal segment may be white or black; the black hair on the mesonotum of the male is not always prevalent. The tomentum on the dorsum of the body varies from yellow to golden yellow. In some specimens the hair on the femora appears pale yellow.

Discussion. This species occurs with G. nigripes and greatly resembles that species. The two can be separated by the genitalia. In G. monticola the projection on the ventral surface of the gonocoxa is much smaller and not as obvious as in G. nigripes (cf. Figs. 43 and 45 ).

Biology. Immature stages unknown. Adults have been taken at flowers of Eriogonum fasciculatum .

Distribution: United States (California).

Etymology. The specific epithet derives from the Latin “ montanus ” = mountains, plus “– cola ” = dweller, inhabitant; referring to the mountainous habitat of this species in the San Bernardino Mountains of southern California.

Figures

FIGURES 42 – 45. Geron male genitalia. 42, G. johnsoni Painter; a, lateral view; b, tip of gonocoxa, ventral view. 43, G. monticola Hall & Evenhuis, sp. nov.; a, lateral view; b, gonocoxa, dorsal view. 44, G. nevadensis Hall & Evenhuis, sp. nov.; a, lateral view; b, tip of gonocoxa, dorsal view. 45, G. nigripes Painter; a, lateral view; b, gonocoxa, ventral view.

FIGURES 13 – 18. Geron vaginal furcae. 13, G. monticola Hall & Evenhuis, sp. nov. 14, G. nevadensis Hall & Evenhuis, sp. nov. 15, G. nigripes Painter. 16, G. notios Hall & Evenhuis, sp. nov. 17, G. painteri Hall Evenhuis, sp. nov. 18, G. parvidus Painter.