Geron confusus 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 : 24-26

Geron confusus Hall & Evenhuis , sp. nov.

Description. Male. Head. Front silver­white tomentose, pile wanting; antenna black; scape with white hair; pedicel with short black hair; first flagellomere evenly tapering from broad base to acuminate apex; antennal ratio: 15:5:30; face cinereous pollinose, white pilose, bare medially, silver tomentum lateral to antennal base; oral margin pale; proboscis projects beyond oral margin for a distance about two times head height; gena white pilose and tomentose; occiput with white hair, lower half with white tomentum; ocellar tubercle with black hair.

Thorax. Mesonotum velvety black, side lightly cinereous pollinose; median longitudinal stripe not evident; notum with white hair, posterior half with short black hair medially; sparse yellow tomentum on posterior half; pleura white pilose and tomentose; legs black, mid and hind tibiae a little lighter; legs with white hair and scales; halter with stem and knob yellowish; scutellum white pilose, tomentum wanting.

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

Abdomen. White pilose, dorsum with pale yellow tomentum, side and venter white tomentose; tergites with lateral margins narrowly pale; sternites with posterior margins narrowly pale.

Genitalia ( Fig. 35 ) with gonocoxa in ventral view with two pits separated by a longitudinal ridge, in lateral view shoe shaped, lower margin straight without projections; gonostylus slightly enlarged basally, about two and one­half times longer than high, narrowly rounded apically; lateral ramus narrow, coextensive with gonostylus; dorsolateral ramus large, bent upward at a right angle.

Female. As in male except as follows: Head. Eyes at vertex separated by slightly more than one and one­half times width of ocellar tubercle; front with pale yellow hair, tomentum golden yellow medially, white laterally along eye margin; occiput with yellow tomentum on upper half; ocellar tubercle with yellow hair. Thorax. Mesonotum with median longitudinal stripe extending beyond transverse suture; fore tarsi with palynophilic setae.

Abdomen. Dorsum with yellow hair, tomentum golden yellow, abundant. Genitalia with posterior projection of tergite VIII black; vaginal furca ( Fig. 6 ) complicated, upper half with struts very narrow, nearly V­shaped; lower half composed of three parts (each side), lateral strut enlarged basally and attached at base of lateral strut is a V­shaped strut with inner margin projecting upward; attached laterally is a kidney­shaped piece (attachment is membranous and thus appears as if the lateral piece is removed from the strut).

Types. Holotype male and allotype (“Skeleton Canyon, Peloncillo Mtns., Cochise County, Arizona, 24.viii.1962, H.V. Weems, Jr.”). [The labels read as above, but the locality is actually in Hidalgo County, New Mexico since the canyon is on the New Mexico side of the border of Arizona and New Mexico]. Paratypes. New Mexico. Hidalgo County: 7, topotypic, collected with types, 2, topotypic, 16.viii.1968 (J.D. Heppner). Texas. Jeff Davis County: 16, Aguja Canyon, Davis Mts., 9.vi.1958 (R.H. & E.M. Painter). Arizona. Cochise County: 4, Copper Canyon, Huachuca Mts. 16.v.1961 (R.H. & E.M. Painter). Holotype and allotype deposited in FSCA. Paratypes deposited in USNM and UCR.

Variation. Little variation, other than slight differences in color intensity, has been noted.

Discussion. The shape of the female vaginal furca should distinguish this species from the congeners, there being no other species seen with which it might be confused.

Biology. Immature stages unknown. Adults have been collected at flowers of Lepidium thurberi .

Distribution. United States (Arizona, New Mexico, Texas). Etymology. The specific epithet derives from the Latin “ confundo ” = mixture, confusion; referring to the confusion of the actual type locality in New Mexico rather than Arizona.

Figures

FIGURES 34 – 37. Geron male genitalia. 34, G. borealis Hall & Evenhuis, sp. nov.; a, lateral view; b, tip of gonocoxa, ventral view. 35, G. confusus Hall & Evenhuis, sp. nov.; a, lateral view; b, tip of gonocoxa, ventral view. 36, G. cressoni Hall & Evenhuis, sp. nov.; a, lateral view; b, tip of gonocoxa, ventral view. 37, G. elachys Hall & Evenhuis, sp. nov.; a, lateral view; b, gonocoxa, 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.