The following material taken with permission from: Mitchell, T.B. 1962. Bees of the Eastern United States, Volume II. North Carolina Agricultural Experiment Station. Tech. Bul. No.152, 557 p.
This genus is related to Xenoglossa and also commonly visits squash blooms. These bees are smaller, but the venation of the front wing is quite similar. The clypeus is slightly separated from the margin of the eye, the resulting space little if any greater than the narrow malar space. In the female the clypeus is black, that of the male black basally, with a more or less extensive yellow maculation apically. The female mandibles are bidentate at apex, and the scopal hairs of the hind tibiae and basitarsi are simple. The basal segment of the flagellum in the female approximates the combined length of segments 2 and 3, but in the male the basal segment is short, about a third the length of segment 2, the following segments about twice as long as broad. Terga 6 and 7 in the male are simple, lacking any lateral angles or spines.
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 12.5-14 mm., breadth of abdomen 5-5.5 mm.; black, the mandibles obscurely yellowish toward apex, apical tarsal segments brownish-testaceous, spurs pale yellowish, tegulae yellowish-hyaline; wings subhyaline, veins piceous to black; cheeks much narrower than eyes; clypeus rather strongly protuberant, its median length about half the distance between eyes (fig. 71); eyes subparallel; mandibles obscurely bidentate at apex; basal segment of flagellum about equal to segments 2 and 3 combined; punctures of clypeus coarse and contiguous, becoming slightly separated along upper margin; labrum quite coarsely and closely punctate throughout, apical, margin subtruncate, very shallowly emarginate medially; supraclypeal area rather sparsely punctate medially, lateral surfaces of face below level of antennae quite deeply, closely and rather finely punctate, surface above antennae somewhat more shining, punctures more minute but rather close, a limited area below anterior ocellus polished and impunctate; cheeks very finely and closely punctate beneath the rather dense pubescence; scutum somewhat shining medially, punctures rather coarse, well separated but not sparse, the peripheral punctures somewhat finer and considerably closer; scutellum very finely and closely punctate; pleura dull, punctures shallow and rather vague, somewhat separated in general; posterior face of propodeum polished and largely impunctate, dorsal area becoming rather coarsely reticulate along upper margin, lateral faces finely and closely punctate beneath dense pubescence; basal abdominal tergum with fine punctures across basal half of disc, these becoming very close and more distinct laterally where they nearly reach the apical margin, the median punctures more minute and sparse, apical margin rather broadly impunctate; punctures on discs of terga 2-4 fine and quite close in general, especially at each extreme side, rather well separated medially on 2, but quite uniformly close en 3 and 4, apical impressed areas invaded in part by minute and rather close punctures, the rims narrowly impunctate; pygidium triangular, apex rather narrowly rounded; pubescence of head, thorax and legs entirely pale ochraceous, somewhat more fulvous on dorsum of thorax, quite copious and elongate on head, somewhat shorter but dense on thorax; hind tibial scopa pale ochraceous, the hairs elongate and rather sparsely plumose; basal abdominal tergum with copious, erect and elongate, pale ochraceous pubescence basally and laterally, the rather narrow apical margin bare; tergum 2 pale pruinose across base, this largely hidden by basal tergum, apical impressed area covered in part by pale tomentum, forming a rather broad but indefinite fascia, the apical rim bare; apical half of terga 2 and 3 largely covered with pale tomentum, forming a broad fascia, basal areas of terga very finely and thinly short pubescent, somewhat pruinose on 3 and 4; apical half of tergum 5 densely covered with long, pale fulvous hairs, and 6 fulvous pubescent on each side of pygidium.
MALE—Length 11-13 mm., breadth of abdomen 4-4.5 mm.; black, the median, apical area of clypeus yellow (fig. 71), face otherwise black; labrum somewhat tinged with yel1owish medially; mandibles obscurely yellowish toward apex; legs piceous to black basally, tarsal segments more or less brownish-testaceous, spurs pale yellowish, tegulae yellowish- hyaline; wings subhyaline, veins testaceous to piceous; cheeks considerably narrower than eyes; clypeus strongly protuberant, its median length slightly greater than half the distance between eyes; eyes subparallel; mandibles obscurely bidentate at apex; basal segment of flagellum rather short, but much longer than pedicel, segment 3 twice as long as basal segment, segment 2 longer than 3; punctures rather coarse, slightly separated on upper half of clypeus, becoming somewhat finer and closer apically, quite obscure on each side; labrum shining, punctures quite deep and distinct but rather fine, slightly separated, median length considerably less than basal width, apical margin quite broadly truncate; supraclypeal area rather dull, sparsely punctate medially, lateral surfaces of face below level of antennae rather dull, punctures quite coarse and close, surface above antennae becoming somewhat more shining, punctures quite close, minute and vague; cheeks minutely punctate along margin of eyes, punctures becoming somewhat more distinct and slightly separated posteriorly beneath the rather long pubescence; scutum somewhat shining medially, the punctures quite coarse and well separated, becoming quite close laterally and anteriorly; scutellum rather dull, punctures quite close and rather coarse; pleura dull, the surface tessellate, punctures shallow, vague and rather sparse; propodeal triangle extensive, polished and impunctate below, becoming rather coarsely, and shallowly reticulate along upper margin, lateral surfaces of propodeum dull, very finely and rather closely punctate; basal abdominal tergum finely and quite sparsely punctate medially, becoming quite closely and deeply punctate laterally nearly to the apical margin, the broad apical median area impunctate; punctures of remaining terga deep and distinct, well separated medially on tergum 2, becoming very fine and almost crowded on the more apical terga, the apical impressed areas invaded in part by minute but rather close punctures, only the rather narrow apical rims impunctate; pubescence of head and thorax copious and erect, entirely pale, rather whitish on face and cheeks below, pale ochraceous on head dorsally and on thorax laterally, somewhat brighter ochraceous or fulvous on dorsum of thorax; legs entirely pale pubescent; basal segment of abdomen with copious, elongate, pale ochraceous pubescence; tergum 2 rather broadly whitish pruinose across base, and apical impressed area thinly pruinose across base, forming a rather distinct greyish-white fascia, intervening area nearly bare, with only exceedingly short, inconspicuous, dark hairs evident; terga 3-6 rather broadly whitish pruinose across apical impressed area, the rims narrowly exposed, discs basally with dark, suberect, more or less elongate pubescence, a few elongate dark hairs overlying the whitish fasciae; tergum 6 not angulate or spinose laterally; median length of pygidial plate much less than basal width, the margins strongly carinate and strongly converging apically to the rather narrowly subtruncate apex; sterna 7 and 8 and genital armature as shown (fig. 72).
DISTRIBUTION — Utah and Arizona, eastward to the New England states and Georgia, June to September.
FLOWER RECORDS — Cucurbita and Pontederia. Recorded by Robertson (1929) on Asclepias, Blephilia, Cephalanthus, Convolvulus, Ipoinoea and Verbena.
The subspeciflc designation of pruinosa is made necessary by the recognition of another subspecies in Southern Texas.