Pogonioefferia rapax (Osten-Sacken)

Lavigne, Robert J. & Dennis, Steve, 2019, Robber flies (Insecta: Diptera: Asilidae) of Wyoming, USA with keys to genera and species, Zootaxa 4662 (1), pp. 1-126 : 43

Pogonioefferia rapax (Osten-Sacken)

Erax rapax Osten-Sacken, 1887: 201 .

Recognition characters: Brown and sliver species; length 20–25 mm; mystax yellowish; bristles and setae of mesonotum of males black except supraalar setae and some postalar setae white, both bristles and setae on female partly white; merals straw white; scutellar setae and bristles black on males, white on females; in males abdominal tergite 3 dorsally and laterally and segments 4–7 silvery white pollinose, long white setae parted in middle and directed outward on tergites 3–6; legs with abundance of yellow setae, femora black, tibiae black anteriorly (some reddish black), brown posteriorly. Can be differentiated from staminea that lacks the patch of short black setae basally and dorsocentrally on abdominal tergite 3 as well as on the basis of the length of the lower arm of the male basistyle that in rapax is not curved downwards.

Distribution: LARAMIE: Laramie, August 1895; Laramie Mtns., August 1895. NIOBRARA: 64 km N of Lusk, July 1895 ( UK); Lusk, 14 July 1937 ( RHB, CLJ-UK). PLATTE: Wheatland, 14 July 1937 ( HTP, CLJ-UK).

Habitat: Pine-douglas fir forest (clearings within the forest where shrubs and grasses are dominant) and gramaneedlegrass-wheatgrass grassland vegetation types. Pine gullies in Great Plains-Black Hills Ponderosa Pine Woodland and Savanna.

Ethology: Nothing known.

Prey: None known.