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

description: Geron senilis (Fabricius)
Bombylius senilis Fabricius, 1794: 411. Turton 1801: 683. Fabricius 1805: 135. Wiedemann 1821: 171.
Geron senilis (Fabricius). Wiedemann 1828: 357. Macquart 1846: 119. Osten Sacken 1858: 43. Osten Sacken 1877: 264. Osten Sacken 1878: 94. Coquillett 1894: 111. Johnson 1894: 275. Aldrich 1905: 245. Johnson 1908: 72. Kertész 1909: 99. Johnson 1910: 747. Johnson 1913: 58. Walton 1915: 173. Cockerell 1917: 14. Sturgis 1918: 28 (as “ semlis ”). Johnson 1919: 429. Cole & Lovett 1921: 251. Painter 1932: 144, 165, 166. Priddy 1939: 47. Painter & Painter 1962: 18. Hull 1973: 204, 206. Painter, Painter & Hall 1978: 17. Evenhuis 1983: 488. Scarbrough & Davidson 1985: 1241, 1242. Evenhuis & Greathead 1999: 48. Godinez Alvarez 2003: 24.
Geron albaria Painter, 1932: 145, 159. Byers et al. 1962: 143. Tabet 1974: 20. Tabet & Hall 1984: 32.
Geron albarius Painter. Painter & Painter 1965: 422 (emendation). Hull 1973: 206. Miller 1978: 42. Frommer 1981: 35. Evenhuis 1983: 462. Tabet & Hall 1987: 67. Poole & Gentili 1996: 70.
Bombylius insularis Bigot, 1857a:332 (1857b: 792).
Geron insularis (Bigot). Osten Sacken 1878: 94. Aldrich1905: 245. Kertész 1909: 99. Painter & Painter 1962: 47. Painter, Painter & Hall 1978: 17. Evenhuis 1983: 476. Scarbrough & Davidson 1985: 1242.
Geron antologos Tabet, 1979: 185. Evenhuis 1983: 463. Nomen nudum.
Geron antologos Tabet, 2001: 49. Syn. nov.
Description. Male. Head. Front silvery tomentose, pile usually wanting; antenna black; scape and pedicel white pilose; first flagellomere linear, evenly tapering from base to acuminate apex; antennal ratio: 9:3:30; face cinereous pollinose, bare medially, silvery tomentum opposite antennal base; oral margin white; proboscis extends beyond oral margin for a distance approximately two times head height; gena white pilose and tomentose; occiput white pilose, silvery tomentum on lower half next to eye margin, wanting on upper half; ocellar tubercle with dark yellow hair.
Thorax. Mesonotum velvety black, side and anterior margin lightly cinereous pollinose; median longitudinal stripe brownish gray, short, broad, not divided, reaches transverse suture; mesonotal pile white to pale yellow anteriorly, dark yellow to black posteriorly, tomentum golden yellow, sparse; pleura white pilose and tomentose; legs black, mid tibia ferruginous, legs with white hair and scales; halter stem brownish; knob white; scutellum with pale yellow hair and golden yellow tomentum.
Wing. Hyaline; venation normal; crossvein r­m at middle of cell dm; vein m­cu sinuous; basicosta with pale yellow hair.
Abdomen. Dorsum white to pale yellow pilose, golden yellow tomentose; side and venter white pilose and tomentose; lateral margins of tergites and posterior margins of sternites narrowly pale.
Genitalia (Fig. 53) in ventral view with gonocoxa flat with two ill­defined lateral, posteriorly converging ridges, median ridge (when present) not prominent; gonocoxa in lateral view rectangular, lower margin without projections; gonostylus long, narrow, four times longer than high; lateral ramus narrow, shorter than gonostylus; dorsolateral ramus short, about half length of lateral ramus.
Female. Eyes separated at vertex by approximately one and one­half times width of ocellar tubercle; front with pale yellow hair, tomentum yellow medially, silvery next to eye margin and immediately above antennae; occiput with yellow pile and golden yellow tomentum on upper half; ocellar tubercle with dark yellowish hair. Thorax. Mesonotum cinereous, median longitudinal stripe narrow, not divided, reaching beyond transverse suture; notum white pilose anteriorly, yellow pilose posteriorly, tomentum golden yellow, abundant; legs black, mid and hind tibiae brownish; fore tarsi with palynophilic setae; scutellum with yellow hair and golden yellow tomentum. Abdomen. Dorsum yellow pilose, golden yellow tomentose. Genitalia with posterior projection on tergite VIII black; vaginal furca (Fig. 22) usually heavily sclerotized, upper half narrowly V­shaped, lower half stout, lateral arms thick, tapering from narrowed base to outwardly curved apex, inner margin at apex swollen, giving a somewhat bilobed appearance, without internal rami.
Types. Lectotype male of Bombylius senilis (“ America meridionalis insularis ”) in the Lund and Sehestedt Collection, ZMUC designated by Scarbrough & Davidson (1985: 1244); not seen by authors. Lectotype male of G. insularis (Cuba) in MNHN studied and designated by Painter & Painter (1962: 47); seen by junior author. Holotype male of G. albaria (Brownwood, Texas, 18.vii.1921, R.H. Painter) and allotype female (Brownwood, Texas, 23.vii.1921, Painter) both in USNM (No. 44869). Holotype male of G. antologos (12 mi. H. Gooding, Gooding Co., Idaho, 11.viii.1977, on Grindelia squamosa, A.B. Tabet) in CAS (No. 14296). Types of G. albaria studied by senior author.
Material Examined. United States. Arizona. Pima County: 2, Molino basin, Santa Catalina Mtns., milepost 4 Hitchcock Hwy, 29.iv.1961 (R.H. & E.M. Painter) (USNM). California. Kern County: 1, Freeman, 1.viii.1956 (T.R. Haig) (UCR). Inyo County: 1, 12 mi. E. Keeler, 7.vii.1982 (J.C. & E.M. Painter) (UCR); 13, Lone Pine, Diaz Lake, 14.vi.1972 (J.D. Pinto); 4, 1 mi. N. Lone Pine, 12.vi.1964 (M.E. Irwin) (UCR). Modoc County: 18, 5 mi. E. Newell, 17.vii.1980 (J.C. & E.M. Hall) (UCR). Riverside County: 1, Whitewater Canyon, 11.ix.1935 (P.H. Timberlake) (UCR); 12, Santa Rosa Mtn., 2.vi.1987 (J.C. Hall) (UCR); 1, Smith Water Canyon, 30.viii.1986 (K.W. Cooper) (UCR). San Bernardino County: 6, Morongo Valley, 5.x.1934 (A.L. Melander) (USNM). Idaho. Bonneville County: 5, 11 mi. W. Idaho Falls, 7.viii.1958 (R.H. & E.M. Painter). Illinois. 1, [southern] (Robertson) (USNM). Maryland. Montgomery County: 1, Plummer’s Island, 20.vii.1913 (W.L. McAtee) (USNM). Montana. Madison County: 1, Gardiner, 20.viii.1918 (A.L. Melander) (USNM). Missoula County: 1, Missoula, 16.viii.1904 (USNM). Nevada. Lyon County: 2, 25 mi. NE Fernley, 29.viii.1956 (T.R. Haig) (UCR). Washoe County: 1, 2 mi. N. Nixon, 16.ix.1972 (J.D. Pinto) (UCR); 1, Patrick, 16.vi.1964 (A.G. Gillogly) (UCR). Pershing County: 1, 20 mi. S. Lovelock, 30.viii.1957 (R.W. Lauderdale) (UCR). New Jersey. Gloucester County: 2, Malaga, viii.1940 (G.M. Greene) (USNM). New Mexico. Hidalgo County: 3, 7 mi. SE Rodeo, 21.viii.1958 (R.E. Rice, G.B. Pitman, D.D. Linsdale) (UCB). Nevada. Lyon County: 6, 25 mi. NE Fernley, 29.viii.1956 (T.R. Haig) (UCR). Utah. Iron County: 2, Anderson’s Wash, 29.vi.1919 (USNM); Cane County: 3, Bryce Canyon N.P. 27.viii.1957 (R.H. & E.M. Painter) (USNM). Virginia. Fairfax County: Mt. Vernon, 4.vii.1917, on flowers of Xolisma ligustrina (W.L. McAtee) (USNM). Washington. Grant County: 4, Stratford, 4.ix.1920 (R.C. Shannon) (USNM). Garfield County: 1, Wawai, 30.viii.1908 (N.M. Mann) (USNM). Douglas County: 1, Wonatchoo, 8.vi.1919 (A.L. Melander) (USNM). Mexico. Durango: 4, Los Nieves, 8700 ft., 5.ix.1962 (R.H. & E.M. Painter) (USNM). Oaxaca: 3, 4 mi. E. Salina Cruz, 7.ix.1963 (R.H. & E.M. Painter) (USNM). San Luis Potosí: 2, 40 mi. N. San Luis Potosí, 8.viii.1963 (R.H. & E.M. Painter (USNM). Veracruz: Cordoba, reared from larval case of Tineola uterella Walsingham, adult issued 2.iv.04 (F. Knab) (USNM). Jamaica. 3, South West Point, 23.viii.1984, dry scrub (N.E. Woodley) (USNM).
Variation. Nearly all of the diagnostic characteristics are subject to variation, however, the majority of the specimens studied have yellow tomentum on the front of the head and along the dorsum of the body. In the male genitalia the venter of the gonocoxa may have two shallow depressions not separated by a definite ridge. There appears to be considerable variation in the development of the apical lobes and in the degree of sclerotization. The apical lobes vary from slightly swollen on the lower inner margin, to bilobed, to greatly swollen on the lower inner margin. In general, specimens within local populations are usually quite uniform as to the shape of the vaginal furca, but there appears to be too much inter­population variation and overlap to be able to consider treating the species listed in the synonymy above as subspecies.
Discussion. This species is much like G. albidipennis. The male genitalia show only slight differences, the two depressions and the strong median dividing ridge are more prominent in G. albidipennis. The vaginal furca in the female of G. senilis has the lower half not as stoutly developed as in G. albidipennis and the spine on the lower surface is less developed. The vaginal furca also exhibits some resemblance to that of G. argutus. In the latter species the apex of the lower half of the apodeme is bent outward, foot­like, and there are no swellings or lobes.
Evenhuis & Greathead (1999) synonymized G. antologos (then a nomen nudum) under G. senilis based on unpublished notes in this manuscript regarding similar configuration of the male genitalia. The subsequent valid publication of G. antologos by Tabet (2001) requires it to be formally synonymized here.
Biology. One single female specimen in the USNM collection has labels stating that it was reared from the larval case of Tineola uterella Walsingham from Cordoba, Mexico. There is no associated pupal case pinned with this specimen. Adults have been taken at flowers of Xolisma ligustrina, Stipulicida setacea, Grindelia squamosa, Chaenactis douglasii and Salsola sp. Tabet (1974) hypothesized that because of the pattern of collections of this species (as G. albaria) in Deep Canyon, California, it might exhibit trivoltinism.
Distribution. United States (Arizona, California, Colorado, Florida, Idaho, Illinois, Kansas, Maryland, Montana, Nevada, New Jersey, New Mexico, Texas, Utah, Virginia, Washington, Wyoming); Mexico (Durango, Nuevo León, Oaxaca, Puebla, San Luis Potosí, Veracruz); Bahamas; Cuba; Jamaica; U. S. Virgin Is; Puerto Rico.
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 55-58, DOI: 10.5281/zenodo.156842