Stenodynerus blepharus

Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region
CJAI 05, February 19, 2008
doi: 10.3752/cjai.2008.05

Matthias Buck, Stephen A. Marshall, and David K.B. Cheung

Department of Environmental Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1

Next species | Previous species | Key

55. Stenodynerus blepharus Bohart, 1953
Figs B7.11, 13, 17, 19, 59; C55.1–4.

Species recognition. Stenodynerus blepharus belongs to a group of species that is characterized by an eyelid-like, transverse swelling behind the mid ocellus. The male is unique for its subshining, black area of flagellomere IX (opposite flagellomere XI), that is clearly delimited from the surrounding dull surface of the flagellum. In other species the same area is dull as the remainder of the flagellum. The female differs from other species by the absence of elongate, oblique, lateral, yellow spots on tergum 1 (the spots are either absent or small, roughly circular or short-triangular and almost always connected to the apical fascia).

Variation. Fore wing length 4.8–5.5 mm (♂♂), 5.5–6.3 mm (♀♀). Thickening of apical margin of tergum 2 0.7–1.0x mid ocellar diameter (male) or 0.4–0.8x mid ocellar diameter (female). Female clypeus with a pair of small to large yellow dorsal spots that sometimes coalesce to form a crescent-shaped mark; rarely clypeus almost completely black; male clypeus yellow with black apicolateral margins and in most cases a small to large, more or less irregularly shaped, central black spot, that is sometimes connected to the black margin ventrolaterally or ventrally. Transverse pronotal band entire or briefly interrupted medially, hind margin on each side straight and oblique to strongly outwardly arcuate. Yellow posteromedian spot of scutum rarely absent in male. Female propodeum often with a pair of yellow lateral spots, better developed dorsally than ventrally, sometimes extending to all the way from dorsum to submarginal carina, but often with multiple interruptions; male propodeum completely black. Female terga 1–4 or 5 and male terga 1–5 or 6 with apical fasciae (in male often completely absent or weakly developed on terga 3–6), fascia of tergum 3 usually represented by small lateral spots, rarely better developed but always broadly separated. Lateral spots of tergum 1 present or absent in female, absent in male, if present almost always connected to apical fascia or else very small; discal spots of tergum 2 very small to evanescent in one male. Sternum 2 with apical fascia; sides of sternum 3 with apical spots; in male sometimes with laterally interrupted or nearly complete apical fascia, these sometimes completely absent.

Distribution. Canada: newly recorded from Carolinian region in ON. Eastern U.S.: NY (new state record: 3 ♂♂ 1 ♀, det. R.M. Bohart, from Huntington, L.I., AMNH), and MD south to FL and west to WV, KS and TX (Krombein 1979). A Floridian form with predominantly red tergum 1 has not been formally named, and is not included in Bohart’s (1948b) key.

Biology. Unknown.

Next species | Previous species | Key