Synonyms and other taxonomic changes
Identification: Black area on abdominal segment 1 is small, sub-triangular. Stripes medium yellow, fading to white on last few abdominal segments. Median lines on thorax touch collar. Female abdomen tip mostly bare.
Head: Black with yellowish hairs around antenna bases on female. Male face covered with yellow hair. Lower face (clypeus) has no center longitudinal ridge.
Antenna: Black; base (scape) and segment 1 may have some reddish-brown to orange.
Thorax: Black with thin, intermittent yellow lines around all segments. Collar has thick yellowish pile. Segment 1 (scutum) has two yellow median stripes, one on each side of an indented center line. These stripes touch the collar (lines widen on male). Segment 2 (scutellum) has tooth at each side edge long and slender (axillae). Segment 3 (propodeum) has line of hairs along outside edges. Thorax side has dark tubercle with yellow fringe. Under tubercle is another crescent or lunate mark. Tufts of hair behind and below wing bases. No yellow hair on underside.
Wings: Wings evenly tinted; not darker at tips. Veins dark.
Legs: Thighs (femora) dark, tips light. Shins (tibiae) and feet reddish-brown, infused with dark streaks. Spurs dark. Underside of legs may have yellowish pile.
Abdomen: Black with yellow stripes, color fades on last few segments.
Segment 1 has two stripes; the sides thickly joined together. Center black area is small and sub-triangular. Both stripes are slightly interrupted at center.
Segment 2 stripe complete across segment; small mark above stripe at each side edge, squarish; smaller or absent on male.
Segment 3 stripe complete across segment.
Segment 4 stripe also compete, but paler.
Female segment 5 has only scattered whitish hairs. No white crescent. Tip squared.
Female underside dark, rarely with some white pile on sides of 2 and 3, but no stripes.
Male segment 5 stripe is narrow, whitish, continuous across segment.
Segment 6 usually without stripe, but may have a small white dash at center.
Male underside of segments dark, rarely with some white pile on sides of 2 and 3, but no stripes; 4 has fringe of long brown curved hairs; 5 has only very short brown hair.
Canada: Ontario. USA: Arkansas, Georgia, Illinois, Indiana, Iowa, Kansas, Louisiana, Michigan, Minnesota, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Texas.
Forest edges and meadows.
Larvae are cleptoparasites of Digger or Long-horned bees Melissodes, possibly Melissodes communis.
Lectotype Triepeolus simplex female by Robertson 1903. #18665 or #3600. Locality Carlinville, Illinois Aug 14, 1896. In Illinois Natural History Survey. Lectotype designated by LaBerge June 20, 1996.
Michigan Museum of Natural History has 4 Triepeolus simplex specimens.
Not a type specimen, but there is 1 listed for the Smithsonian – no photos.
Similar Species: On Triepeolus lunatus the thorax mid stripes do not touch collar, underside of abdominal segments 2 to 4 are striped, clypeus has a ridged midline and the female has a crescent on abdomen tip.
The Canadian Entomologist, 1903, Vol. 35, pp. 285 to 286 keys by Robertson.
North Carolina Agricultural Experiment Station, 1962, Technical Bulletin #152: Bees of the eastern United States by Mitchell.
University of Kansas, 2006: Phylogenetic Analysis of Epeolini – Triepeolus, Thesis by Rightmyer.
Zootaxa 2008, #1710: A review cleptoparasitic Triepeolus Part I by Rightmyer – repeat information.