Geron niveus Cresson

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 : 43-44

Geron niveus Cresson

Geron nivea Cresson, 1919: 185 . Cole 1923: 311. Hull 1973: 206.

Geron niveus Cresson. Painter & Painter 1965: 423 (emendation). Evenhuis 1983: 482. Poole & Gentili 1996: 71. Evenhuis & Greathead 1999: 42.

Description. Male. Head. Front with silver scales and white hair; antenna black; scape and pedicel with white hair; first flagellomere narrow, tapering evenly from base to acuminate apex; antennal ratio: 16:6:30; face cinereous pollinose, white pilose, bare medially; tomentum silver­white, restricted to side along eye margin; oral margin pale; proboscis projects beyond oral margin for a distance about two and one­half times head height; gena white pilose and tomentose; occiput white pilose, white tomentum on lower half; ocellar tubercle with pale yellowish hair.

Thorax. Mesonotum dull black; side and anterior margin cinereous pollinose; median longitudinal cinereous stripe short, medially divided; notum white pilose, tomentum golden yellow, scattered; pleura white pilose and tomentose; legs black with white pile and tomentum; mid and hind tibiae and basitarsi ferruginous; halter with stem and knob whitish; scutellum white pilose, tomentum yellow, scattered.

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

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

Genitalia ( Fig. 46 ) with gonocoxa in ventral view with two shallow depressions but without a median dividing ridge; gonostylus long, narrow, rounded apically; lateral ramus narrow, slightly curved, coextensive with gonostylus; dorsolateral ramus prominent, long and broad.

Female. As in male except as follows: Eyes separated at vertex by two and one­half times width of ocellar tubercle; front white pilose and tomentose, a few small golden scales medially; ocellar tubercle with a few short black hairs; occiput with golden yellow scales on upper half; tomentum on body golden yellow, dense. Genitalia not dissected.

Types. Holotype male of G. niveus (East Highlands, California, 15.ix.1914) in ANSP (No. 6209). The type is in good condition, except the right third antennal segment and the left middle leg are missing. The genitalia have been dissected and placed in a microvial attached to the pin. Studied by senior author. This species is only known from the type series.

Variation. This species is known only from the type and two paratypes so nothing can be said concerning variation.

Discussion. The original description states that F.R. Cole collected the specimens although this is not stated on the labels. However, this is probably correct since the locality on the labels on the three specimens studied (East Highlands) was one of Cole’s favorite collecting sites. The male genitalia are very similar to that found in G. senilis . Biology. Immatures stages and adult flower preferences unknown.

Distribution. United States (California).

Figures

FIGURES 46 – 49. Geron male genitalia. 46, G. niveus Painter; a, lateral view; b, tip of gonocoxa, dorsal view, epiphallus removed. 47, G. notios Hall & Evenhuis, sp. nov.; a, lateral view; b, gonocoxa, dorsal view. 48, G. painteri Hall & Evenhuis, sp. nov.; a, lateral view; b, tip of gonocoxa, ventral view. 49, G. parvidus Painter; a, lateral view; b, gonocoxa, dorsal view, epiphallus and phallic complex removed.