Reprinted with permission from: Mitchell, T.B. 1960 Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 141. |
FEMALE—Length 6 mm.; black to piceous; distance between eyes about three-fourths length of face; eyes subparallel; cheeks considerably narrower than eyes; process of labrum about as long as basal width, narrowed to about one-half at truncate apex; facial foveae distinct, terminating about at level of antennae; lateral ocelli subequally distant from each other and margin of vertex; median segments of flagellum very slightly longer than broad; punctures of head deep and distinct, fine and close above antennae, becoming more distinctly separated laterally and on vertex, quite sparse below antennae and on cheeks below; pubescence of head and thorax entirely pale, short, thin and obscure; tubercles yellow; tegulae yellowish-hyaline; wings sub-hyaline, veins pale testaceous, stigma more brownish, 2nd recurrent vein entering 2nd submarginal cell considerably nearer apex than 1st does to base; legs entirely dark, tibial scopa loose and rather thin, but distinctly plumose; spurs yellow; thoracic integument shining, punctures of scutum rather fine and irregular, quite sparse except along narrow anterior margin, those on scutellum rather close and fine anteriorly, becoming coarser and more sparse posteriorly, those on pleura coarser and closer; apical margins of abdominal terga rather broadly and shallowly depressed, these areas reddened, shining and impunctate, discs of the terga shining, very finely and sparsely punctate, punctures somewhat closer along basal margins of discs and at extreme sides, discal pubescence entirely pale, very thin, sparse and obscure, forming a quite dense, pale brownish, apical fimbria on tergum 5.
MALE—Length 6 mm.; black to piceous; distance between eyes above about three-fourths length of face; eyes subparallel; lateral apical margins of clypeus blackish, clypeus otherwise yellow; process of labrum, mandibles, a spot on supraclypeal area and lateral maculae, all yellow, the facial maculae triangular, extending along eye margin about to level of antennae; cheeks considerably narrower than eyes; length of process of labrum sub- equal to its basal width, considerably narrowed to the truncate tip; facial foveae small but distinct; lateral ocelli subequally distant from each other and from margin of vertex; median segments of flagellum considerably longer than broad; punctures of head quite deep and distinct, close above antennae and on cheeks, becoming somewhat more sparse laterad of ocelli and below antennae; pubescence of head and thorax entirely pale, very short, thin and sparse; tubercles yellow; tegulae yellowish hyaline; wings sub-hyaline, veins pale testaceous, stigma somewhat more brownish; 2nd recurrent vein entering 2nd submarginal cell somewhat nearer apex than 1st does to base; tarsi and spurs yellow, tibiae yellow at extreme apex, front tibiae yellow anteriorly, mid tibiae yellow over basal fourth, and hind tibiae over nearly the basal half; punctures of thorax quite deep and distinct, rather coarse, well separated but hardly sparse over scutum and scutellum, those on pleura considerably coarser and somewhat more sparse above, becoming close beneath; apical margins of abdominal terga rather deeply and evenly depressed, these areas smooth and shining, impunctate, discs shining, that of basal tergum being very minutely and sparsely punctate, punctures on 2nd and following terga deeper and more distinct, quite close toward base, becoming sparse apically, discal pubescence very short, thin and sparse, entirely pale; sternum 6 deeply and narrowly emarginate medially; wings of sternum 7 sub-acute apically, tips slightly recurved, with a fringe of rather short setae; apical process of sternum 8 very short, tip truncate and slightly expanded, bearing a double tuft of setae; gonostyli very slender, somewhat recurved, with a submedian inferior angle, tip abruptly flexed and very slender, bearing a subapical tuft of rather long setae; penis valves quite slender, about attaining tips of gonostyli.
DISTRIBUTION — Minnesota to New York, south to North Carolina; August and September.
FLOWER RECORDS — Heliopsis, Rudbeckia lanceolata. Robertson (1929) records this on Helianthus divaricatus, H. tuberosus and Rudbeckia triloba.
In the Catalog of Hymenoptera (Michener, 1951) labrosus is listed under the subgenus Heterosarus. The elongate basal segment of the labial palpus and the distinctly plumose tibial scopa indicate a closer relationship with the species of Pseudopanurgus s. str.