Reprinted with permission from: Mitchell, T.B. 1962 Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 152.|
FEMALE—Length 12-18 mm.; black, tegulae more brownish-piceous, tarsal segments bright ferruginous, the tibiae and femora sometimes more or less ferruginous; eyes slightly convergent below; lateral ocelli slightly nearer margin of vertex than to each other, considerably more distant from eyes; cheeks considerably narrower than eyes, carinate posteriorly, angulate below, but this area covered with dense pubescence; clypeus nearly flat, apical margin about straight, with a fringe of rather short but dense pubescence; median length and basal width of labrum about equal; median tooth of mandible low but distinct; punctures deep and quite coarse, close but distinct across vertex, cheeks and face below ocelli coarsely rugose, becoming finely rugose below antennae and on clypeus; pubescence entirely pale on head and thorax, somewhat yellowish on face, copious around antennae and behind anterior ocellus, very short, dense and subappressed at sides of face, laterad of clypeus, thin and very short and obscure over most of clypeus, dense and white on cheeks below, becoming thin above; pubescence rather short but quite copious over pleura, more elongate and whitish on propodeum, very thin and inconspicuous on dorsum of thorax; transverse carina of tubercles rather low but distinct, more or less obscured by pubescence; posterior margin of scutellum slightly out- curved, posterior face not sharply differentiated from dorsal face; axillae acute, projecting conspicuously from sides of scutellum, but length not exceeding median length of scutellum; coxal spines reduced to short but acute tubercles which are densely pubescent posteriorly; wings hyaline basally, becoming very faintly infuscated apically, recurrent veins reaching 2nd submarginal cell subequally distant from base and apex; scutum coarsely, closely and deeply impunctate, punctures slightly separated only in center posteriorly, densely crowded and somewhat finer laterally, but distinctly separated to anterior margin; scutellum coarsely rugoso-punctate or reticulate, the axillae somewhat more finely so; pleura more reticulate than punctate, punctures coarse and closely crowded; lateral faces of propodeum somewhat smoother but very dull, posterior face dull, with closely crowded, minute punctures, dorsal area smooth but velvety, becoming narrowly substriate along upper margin; basal abdominal tergum shining, punctures deep and distinct, well separated medially, becoming close laterally, and very close and fine toward the depressed apical margin, this narrowly white fasciate, but becoming rather broadly so at extreme sides; transverse grooves of terga 2 and 3 sub- median at center, becoming somewhat more basal at extreme sides, punctures quite regular, coarse and close on basal side of groove, the apical side being largely impunctate, but with scattered punctures toward the apical margin, this depressed and densely white fasciate; terga 4 and 5 rather closely punctate toward base, sparsely so toward apical margin, the margins depressed and white fasciate; tergum 6 abruptly narrowed just beyond mid point, resulting in a pair of distinct lateral angles, a median, slightly raised, impunctate line at base, continuous with an elevated ridge toward the tip, surface deeply excavated on each side of this, the tip narrowly rounded, punctures toward the base deep, distinct, rather coarse and close, becoming densely crowded at the lateral angles, the apical part finely rugose (fig. 65); sternum 6 elongate, extending much beyond tip of tergum, narrowed apically, with a pair of distinct, lateral notches, this area much longer than width at the notches, rather narrowly rounded at apex; sterna 1-4 shining, closely, coarsely, deeply and quite regularly punctate, apical margins depressed, yellowish-hyaline, densely white fasciate; sternum 5 triangular in outline, basal portion deeply and quite closely punctate, but the punctures becoming rather abruptly fine and densely crowded just beyond base, apical half dull and densely roughened, the oblique, lateral margins densely, white fasciate.
MALE—Length 11-12 mm.; black, tegulae more brownish-testaceous, tarsi ferruginous, and tibiae usually ferruginous basally and apically; eyes rather strongly convergent below; lateral ocelli subequally distant from margin of vertex and each other, considerably more distant from eyes; cheeks slightly narrower than eyes, carinate posteriorly, quite deeply excavated below, this area shining and bare, relatively smooth, margined both anteriorly and posteriorly by dense pubescence; clypeus nearly flat, apical margin straight, with a pair of small, median tubercles; median length of labrum slightly greater than basal width; median tooth of mandible well developed; punctures coarse and deep, well separated across vertex, becoming closely crowded on cheeks, face below ocelli rather finely rugose, surface below antennae and on clypeus obscured by dense pubescence, very finely rugose beneath; pubescence entirely pale. rather creamy on face, somewhat more elongate and erect around bases of antennae, subappressed and directed upward on supraclypeal area, directed downward on clypeus, cheeks below with dense, white pubescence; pleura rather copiously covered with white pubescence, not forming definite marginal fringes, the pubescence becoming somewhat more yellowish but very thin above, elongate and copious over most of propodeum; transverse carina of tubercles erect and well developed on outer side, not extended along margin of scutum, largely obscured by pubescence; posterior margin of scutellum very slightly outcurved, posterior face not sharply differentiated from dorsal face; axillae rather elongate and acute, conspicuously diverging from sides of scutellum, and slightly exceeding median length of scutellum; coxal spines well developed, somewhat spatulate and elongate, rounded apically, densely covered with white pubescence; wings hyaline basally, becoming slightly infuscated along apical margin, recurrent veins reaching 2nd submarginal cell subequally distant from base and apex; scutum coarsely, deeply and closely punctate, punctures slightly separated only in center of disc, becoming somewhat finer and more densely crowded laterally; scutellum rather coarsely rugoso-punctate or reticulate, the axillae only slightly more finely so; pleura dull, rather finely rugoso-punctate or reticulate; lateral faces of propodeum dull, densely tessellate, posterior face dull, very minutely and closely punctate, punctures rather vague, dorsal area velvety below, becoming finely and irregularly rugose along upper margin; basal abdominal tergum shining, coarsely and deeply punctate, punctures well separated medially, but becoming very close at extreme sides, apical margin abruptly depressed, yellowish-hyaline, densely white fasciate. lateral margins of the dorsal face conspicuously white tomentose; transverse grooves of terga 2 and 3 very deep and complete sub-basal on 2 and subapical on 3, but becoming more nearly basal on each one at extreme sides, punctures on basal side coarse, deep, close and quite regular, apical margin of groove more or less impunctate, medially, becoming more coarsely and closely punctate at each extreme side, apical margins abruptly depressed, yellowish-hyaline, densely white fasciate, tergum 2 with a pair of much elongated and very narrow and deep foveae on each side, just apical to the groove; terga 4 and 5 white fasciate across base, apical margins deeply depressed and fasciate at extreme sides, punctures coarse, deep, distinct, close laterally, somewhat more widely separated medially; tergum 6 fasciate across base, surface densely and irregularly rugoso-punctate, rather finely so at sides, with a deep, median concavity, dorsal protuberances short, somewhat divergent, broadly rounded or subtruncate, the ventral spines more elongate and parallel, narrowly sub- truncate apically, lateral spines rather elongate and slender (fig. 66); sterna 1-4 shining, coarsely, deeply and closely punctate, apical margins abruptly depressed, yellowish-hyaline, densely white fasciate on 2 and 3, fasciate toward sides on 4, disc of 4 not emarginate medially but the depressed margin with a very narrow emargination; sternum 5 largely retracted, apical margin slightly incurved medially, with a rather dense, apical fringe on each side; sterna 6 and 8 entirely retracted, 8 rather narrowly subtruncate apically; penis valves of genital armature fully equal to gonocoxites in length, the gonocoxites somewhat compressed, bearing copious elongate and erect pubescence.
DISTRIBUTION—British Columbia and California to Nova Scotia, the New England states, North Carolina and Georgia; June to October.
FLOWER RECORDS—Asclepias, Baptisia, Helianthus, Melilotus, Rudbeckia, Solidago, Spiraea and Vicia. Robertson (1929) lists the following additional plant genera: Aster, Blephilia, Lobelia, Monarda, Petalostemum and Verbesina.
HOSTS—Megachile latimanus Say and M. melanophoea Smith.
The subspecific designation of rufitarsis is made necessary by the present recognition of two additional subspecies in the western states.