Megaphorus guildianus (Williston)

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 : 50

Megaphorus guildianus (Williston)

Mallophora guildiana Williston, 1885: 60 .

Recognition characters: Yellow species; length 9–13 mm; mystax straw white; thorax yellow pilose, scutellar setae yellowish white; scutellar bristles lacking; wings brownish; abdomen yellow pilose, lateral setae on first abdominal segment yellowish white; legs, femora and tibiae orange with thick yellow setae, apex of hind tibiae with majority of bristles black, reddish brown with setae yellow above tarsi.

Distribution: FREMONT: Lander, WANG, LTA, 8 Aug. 2004 ( CSU, GMAD). HOT SPRINGS: Dutch Nick Flats, Big Horn Basin, 25 July 1962 ( CK). GOSHEN: Lingle, 4 Aug. 1965 ( MHB) (specimen in NMSCA). LARA- MIE: Pine Bluffs, 29 July–2 Aug. 1967 ( WAN). NIOBRARA: Lance Creek, 5 Aug. 1995 (Wheeler-AMNH); Niobrara Co., 17 Aug. ( REP, JW), 17 Aug. 1945 ( REP) (specimen in CAS). PLATTE: Glendo, 19 Aug. 1959 (specimen in CAS), 6 July 1964 ( FRH) (specimen in NMSCA); Glendo, 5 Aug. 1959 (specimen in CAS), 5 Aug.–3 Sept. ( REP, JW). Dwyer numerous records, 6 July–3 Sept. ( RJL); Camp Guernsey, WANG, 2001b ( CSU, GMAD); Guernsey, 18 Aug. 1974 ( RJL) (specimen in MNSU, NMSCA); Guernsey, numerous records 14 July–6 Sept. ( LJS, RJL, SD); Twin Pine Ranch, 13 km W of Dwyer, 25 Aug. 1966 ( RJL, MHB); Wheatland, 5–25 Aug. 1964 ( RJL, FRH), 27 Aug. 1965 ( FRH); 37 km N of Wheatland, numerous records, 6 July–29 Aug. ( SD). SHERIDAN: Sheridan, WANG, LTA, 17 July 2006 ( CSU, GMAD); 8 km N Sheridan, 6 Aug. 1963 ( GEB, PT) (specimen in CAS). TETON: Jackson, 21 June 1961 ( VR). Recorded from Wyoming by: Cole & Pritchard, (1964) (Glendo, Lance Creek, Niobrara Co.); Dennis & Lavigne (1975) [as Mallophorina guildiana ; as prey of Proctacanthus milbertii (as Proctacanthus micans )], (1976b) (pupal case; as Mallophorina guildiana ), (1976c) (as prey of Efferia varipes ), (2007) (as Megaphorus guildiana ); Dennis et al. (2008) (pupal case; as Megaphorus guildiana ); Geller-Grimm (2018); Lavigne & Holland (1969) [as Mallophorina guildiana ; as prey of Diogmites angustipennis , Pogonioefferia pallidula (as Efferia pallidula )]; Lavigne et al. (1976) [as Mallophorina guildiana ; as prey of Pogonioefferia benedicti (as Efferia benedicti )], (1994).

Habitat: Sagebrush steppe and wheatgrass-needlegrass shrub steppe shrub and grassland, and grama-needlegrass-wheatgrass and grama-buffalo grass grassland vegetation types. Open range, short- to mid-grass plains in areas having a high forb density (see Dennis & Lavigne 1975, as Mallophorina guildiana ).

Ethology: Usually forages from vegetation, and only rarely lands on the ground or a rock (e.g., when the sun is obscured by clouds) (see Dennis & Lavigne 1975).

Prey: COLEOPTERA , DIPTERA , HEMIPTERA (as Heteroptera and Homoptera), HYMENOPTERA (see Dennis & Lavigne 1975; Rogers & Lavigne 1972, both as Mallophorina guildiana ).