Geron peucon 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 : 48-50

Geron peucon Hall & Evenhuis , sp. nov.

Description. Male. Head. Front with silvery tomentum, hair wanting; antenna black; scape with white hair; pedicel with short black hair; first flagellomere evenly tapering from base to acuminate apex; antennal ratio: 10:4:21, face cinereous pollinose, white pilose, bare medially, silvery tomentum lateral of antennal vase; oral margin pale; proboscis projects beyond oral margin for a distance approximately twice head height; gena white pilose and tomentose; occiput white to pale yellow pilose, white tomentose on lower half, tomentum not dense; ocellar tubercle with dark yellow to black hair.

Thorax. Mesonotum velvety black, lateral margin only vaguely cinereous pollinose; median longitudinal stripe vague, medially divided, short, not reaching transverse suture; notum white to pale yellow pilose, shorter black hair medially behind transverse suture, tomentum wanting; pleura white pilose and tomentose; katepisternum densely white pilose; legs black, with white hair and scales; halter with stem brownish, 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. White pilose, tomentum on dorsum pale yellow, scattered; tergites with lateral margins black; sternites with posterior margins black.

Genitalia ( Fig. 50 ) with gonocoxa in ventral view flat, without depressions or ridges, in lateral view gonocoxa rectangular, lower margin with a small, blunt projection; gonostylus about three times longer than high, slightly bent, bluntly rounded at apex; lateral ramus narrow, curved, apically pointed; dorsolateral ramus long, thick, coextensive with lateral ramus.

Female. As in male except as follows: Head. Eyes at vertex separated by approximately one and one­half times width of ocellar tubercle; front with yellow hair, golden yellow tomentum medially, silver­white tomentum laterally and above antenna; occiput with yellow pile and golden yellow tomentum on upper half; ocellar tubercle with black hair. Thorax. Mesonotum dark yellow pilose, golden yellow tomentose; median longitudinal lightly cinereous pollinose, narrow, reaching transverse suture; scutellum with dark yellow hair and golden yellow tomentum; meron with white hairs and scales; basicosta with yellow hair. Abdomen. Dorsum yellow pilose, golden yellow tomentose. Genitalia with posterior projection of tergite VIII black; vaginal furca ( Fig. 19 ) with upper half narrowly Vshaped; lower half stout, arms curved, apex swollen with a long inward projecting ramus, ramus slightly curved.

Types. Holotype male and allotype (Frazier Park, Kern County, California, 18.vi.1981, J.C. Hall). Paratypes. California. Kern County: 2, topotypic, collected with types; Mono County: 2, Bridgeport, viii.1938, 13.viii.1958 (T.F. Winburn, R.H. & E.M. Painter); Inyo County : 9, Big Pine Creek, 18.viii.1958 (R.H. & E.M. Painter); 3, Bishops Creek, 16.viii.1958 (R.H. & E.M. Painter); 1, 40 mi. N Bishop, 16.viii.1958 (R.H. & E.M. Painter); Mendocino County: 10, 10 mi E Calpella, 15.ix.1959 (T.R. Haig); 10, Hopland, 15.viii.1953) 17–29.vi.1959 (S.M. Fidel); Butte County: 2, Forbestown, 9viii.1957 (T.R. Haig); Tuolumne County: 1, Harding Mill Flat, 17.viii.1952 (J.C. & E.M. Hall); Sonoma County: 1, 3 mi. S Monte Rio, 9.viii.1974 (T. Plichta); Los Angeles County: Tanbark Flat, 12.vii.1950 (J.C. Hall); 2, Bouquet Canyon, 18.vi.1981 (J.C. Hall, N. Evenhuis); 19, Azusa Canyon, 18.ix.1944 (A.L. Melander); Riverside County: 17, Riverside, 16.vii.1934, 8.iii.1935, 22.vi.1954, 22.ix.1963, 15.viii.1969, 7.vii.1978 (P.H. Timberlake, J.C. Hall, M.E. Irwin); 1, Box Springs Mts., 6.vi.1965 (M.E. Irwin); 2, El Cariso, San Juan Camp, 16.vii.1945 (A.L. Melander); 1, 1.5 mi. W Perris, 21.vi.1938 (P.H. Timberlake); 2, Gavilan, 29.v.1946 (P.H. Timberlake); San Luis Obispo County: 3, Baywood Park, 15.ix.1956, 25.x.1970 (J. Wilcox, J.C. Hall); San Bernardino County: 3, Lytle Creek, 10.vii.1968 (M. Wargo); 4, 7 mi. E. Cushenberry 18.vii.1979 (J.C. Hall); 12, Big Bear Lake, 24.viii.1957, 18.vii.1963 (P.M. Estes, E.I Schlinger); 2, Yucca Valley, 5.x.1934 (A.L. Melander); San Diego County: 1, 2 mi. N. Portero, 23.ix.1971 (J.B. Heppner). Nevada. 8, Lehman Creek, 21.viii.1957 (R.H. & E.M. Painter). Utah. 1, Iron County: Cedar City, 22.viii.1959 (E.M. & R.H. Painter); 1, Dividend, 1.ix (T. Spalding). Idaho. Blaine County: 3, 6 mi. SW Carey, 7.viii.1958 (R.H. & E.M. Painter). Arizona. Santa Cruz County: 5, Florida Canyon, Santa Rita Mts., 3.vi.1961 (R.H. & E.M. Painter). Holotype and allotype deposited in USNM. Paratypes deposited in USNM and UCR.

Variation. With the usual color variations. The mid and hind tibiae may be light ferruginous. Specimens from coastal California have darker hair on the upper half of the head.

Discussion. The configurations of the vaginal furca resembles that of G. subauratus , the inward projecting arms however, in the latter species are directed upward; in G. peucon the projections are straighter. The male genitalia are similar to G. nigripes , but differ primarily in the shorter projections on the gonocoxa.

Biology. Immatures unknown. Adults have been taken at flowers of Croton californicus , Lippia lanceolata, Isocomis sp., Hugelia sp., and Brassica sp.

Distribution. United States (Arizona, California, Idaho, Nevada, Utah).

Figures

FIGURES 50 – 53. Geron male genitalia. 50, G. peucon Hall & Evenhuis, sp. nov.; a, lateral view; b, gonocoxa, ventral view. 51, G. prosopidis Hall & Evenhuis, sp. nov.; a, lateral view; b, gonocoxa, ventral view. 52, G. rufipes Macquart; a, lateral view; b, tip of gonocoxa, dorsal view. 53, G. senilis (Fabricius); a, lateral view; b, gonocoxa, dorsal view, phallic complex removed.

FIGURES 19 – 24. Geron vaginal furcae. 19, G. peucon Hall & Evenhuis, sp. nov. 20, G. prosopidis Hall & Evenhuis, sp. nov. 21, G. rufipes Macquart. 22, G. senilis (Fabricius. 23, G. stenos Hall & Evenhuis, sp. nov. 24, G. subauratus Loew.