Geron albipilosus 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 : 17-19

Geron albipilosus Hall & Evenhuis , sp. nov.

Description. Male. Head. Front silvery tomentose, pile wanting; antenna black; scape and pedicel with white hair; first flagellomere evenly tapering from broad base to acuminate apex; antennal ratios 8:3:20; face cinereous, white pilose, bare medially; tomentum lateral of antennal base silvery; proboscis projects beyond oral margin for a distance two times head height; oral margin white; gena white pilose and tomentose; occiput white pilose, white tomentum on lower half; ocellar tubercle with white hair.

Thorax. Mesonotum velvety black, lateral margin cinereous pollinose; median longitudinal stripe short, broad, not reaching transverse suture; notum white pilose with shorter black hair medially on posterior half; tomentum of scattered hair­like pale yellow scales behind transverse suture; pleura white pilose and tomentose; legs black, white pilose and tomentose; halter with stem and knob pale yellow; scutellum white pilose, pale yellow tomentose.

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

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

Genitalia ( Fig. 31 ) with gonocoxa in ventral view flat, without pits or ridges, in lateral view narrowly rectangular, lower margin with two short spurs, first broad, lobe­like, second pointed; gonostylus narrow, about four times longer than high, slightly curved apically; lateral ramus narrow, coextensive with gonostylus; dorsolateral ramus straight, broad, pointed apically.

Female. As in male except as follows: Head. Eyes separated at vertex by two times width of ocellar tubercle; front white pilose and tomentose; occiput pale yellow tomentose on upper half. Thorax. Mesonotum with median longitudinal stripe broad, nearly reaches transverse suture; notum with white hair and pale yellow tomentum; legs with mid and hind tibiae vaguely testaceous; fore tarsi with palynophilic setae. Abdomen. Dorsum with abundant pale yellow tomentum. Genitalia with posterior projection of tergite VIII black; vaginal furca ( Fig. 2 ) simple, upper half broadly V­shaped; lower half with struts narrow, slightly bowed, inner margin near apex slightly swollen, apex with a feebly attached lumplike piece.

Types. Holotype male and allotype (Quemado, Catron County, New Mexico 19.vii.1932, R.H. Painter). Paratypes. California: Inyo County : 2, Deep Springs, 16.vii.1953 (E.I. Schlinger); 1, 5 mi. S Deep Springs 11.vii.1957 (S. & S. Frommer). Colorado: Grand County: 10, 7 mi. NW Alamosa, 23.viii.1963 (N. & B. Marston); Jackson County: 1, Walden, 14.viii.1954 (R.H. Painter), Nevada: Humboldt County: 1, Golconda, 10.viii.1958 (R.H. & E.M. Painter); 7, Valmy, 13.ix.1956 (T.R. Haig); 5, Winnemucca, 30.viii.1956 (T.R. Haig); 3, 20 mi. S. Winnemucca, 4.vii.1957 (T.R. Haig). Lyon County: 4, 10 mi. E Fernley, 5.vii.1956 (T.R. Haig). Pershing County: 3, 8 mi. S Lovelock, 30.v.1958 (T.R. Haig). New Mexico: 16, topotypic, collected with types. Utah: San Juan County: 19, 25 mi. N Monticello, 23.vi.1961 (R.H. & E.M. Painter). Holotype and allotype deposited in USNM. Both specimens mounted on same minuten nadlen. Paratypes deposited in USNM and UCR.

Variation. Little variation has been noted. In some males the mid and hind tibiae are lighter colored than as described. The pile varies from pure white to pale yellow.

Discussion. Similar to G. argutus Painter in pilosity and color of tomentum. In the male genitalia the presence of two projections on the lower margin of the gonocoxa in G. albipilosus versus only one in G. argutus will distinguish the males. The females may be recognized by the characteristic vaginal furca: the swollen apices of the lower struts are pointed inward in G. albipilosus and outward in G. argutus .

Biology. Immature stages and adult flower preferences unknown.

Distribution. United States (California, Colorado, Nevada, New Mexico, Utah). Etymology. The specific epithet derives from the Latin “ albi ­“ = white, + “ pilosus ”= hair; referring to the predominantly pale colored vestiture of this species

Figures

FIGURES 30 ­ 33. Geron male genitalia. 30, G. albipennis Painter; a, lateral view; b, tip of gonocoxa, ventral view. 31, G. albipilosus Hall & Evenhuis, sp. nov.; a, lateral view; b, ventral view. 32, G. arenicola Painter; a, lateral view; b, tip of gonocoxa, ventral view. 33, G. argutus Painter; a, lateral view; b, ventral view.

FIGURES 1 – 6. Geron vaginal furcae. 1, G. albidipennis Loew. 2, G. albipilosus Hall & Evenhuis, sp. nov. 3, G. arenicola Painter. 4, G. argutus Painter. 5, G. borealis Hall & Evenhuis, sp. nov. 6, G. confusus Hall & Evenhuis, sp. nov.