Reprinted from: Rightmyer MG, Griswold T, Arduser MS (2010) A review of the non-metallic Osmia (Melanosmia) found in North America, with additional notes on palearctic Melanosmia (Hymenoptera, Megachilidae). ZooKeys 60 : 37 – 77 . doi: 10.3897/zookeys.60.484|
Diagnosis. Females are known by the slightly acute angle or tooth midway on the
ventral margin of the mandible (Fig. 52). Males can be distinguished by the form of
the S4, which is strongly truncate and emarginate medially, forming distinct, rounded
sublateral lobes (Fig. 60).
Distribution. In the Nearctic, from Sierra Nevada of California north to British
Columbia and Alaska, east through Canada to Nova Scotia and Newfoundland south
in the United States to Massachusetts, Michigan, the Black Hills of South Dakota,
and mountainous areas of Nevada, Utah, and Colorado. In the Palearctic, O. inermis is
found from Spain, Italy, and Greece north to the United Kingdom, Norway, Sweden, and Finland, and east through Russia and northern China (Müller, 2010). The related,
if not synonymous, species O. ishikawai is found in Japan.
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 10 mm.; entirely black, without metallic tints; face slightly longer than distance between eyes above; eyes slightly convergent below; lateral ocelli sub- equally distant from eyes and margin of vertex, somewhat nearer to each other; clypeus broadly convex, apical margin considerably produced, median area quite straight, with a shining, impunctate rim; median length of labrum about equal to basal width; mandibles 3-dentate, as shown (fig. 32); cheeks considerably broader than eyes; wings subhyaline, 2nd recurrent vein reaching 2nd submarginal cell much nearer apex than 1st does to base tarsal segments simple and unmodified, mid and hind spurs piceous; pubescence of head, thorax and basal abdominal tergum yellowish- white, and whitish on basal segments of legs, but becoming black on tibiae and tarsi; scopa black, pubescence on abdominal terga 3-5 black and erect, black apically and pale basally on 2, pale and obscure on 6; punctures rather fine but deep and distinct, close over most of head and thorax, densely crowded on face, slightly separated only in center of scutum; pleura dull, with densely crowded punctures, lateral and posterior faces of propodeum smooth, but dull, without distinct punctures, dorsal area velvety, not becoming definitely striate along dorsal margin; punctures of abdominal terga very fine and slightly separated medially on 1-5, becoming very close at extreme sides, apical margins only slightly depressed, punctures more minute and sparse, the rims slightly reddened and impunctate, punctures of 6 minute and densely crowded.
MALE—Length 9 mm.; entirely black, without metallic tints; face not much longer than distance between eyes above; eyes somewhat convergent below; lateral ocelli subequally distant from margin of vertex and each other, somewhat more distant from eyes; clypeus only slightly convex, apical margin considerably produced, quite straight and narrowly impunctate medially; mandibles bidentate; cheeks considerably broader than eyes; wings subhyaline, recurrent veins reaching 2nd submarginal cell subequally distant from base and apex; tarsal segments slender and unmodified, anterior margin of hind basitarsus with a triangular, submedian tubercle; mid and hind spurs blackish; pubescence entirely yellowish-white, rather copious and erect over entire head and thorax, pale on basal abdominal tergum and in large part on tergum 2, discs of following terga with erect, more or less fuscous but rather thin pubescence; punctures rather deep and distinct but fine and close in general, crowded beneath pubescence on lower part of face, more coarse and distinct above and on cheeks, slightly separated in center of scutum and distinct but quite close on scutellum; pleura dull, with rather shallow, subcontiguous punctures; lateral faces of propodeum rather smooth but dull, punctures close but vague and indistinct, posterior face dull and tessellate punctures hardly evident, dorsal area velvety, not definitely striate along upper margin; punctures of abdominal terga minute, but quite close on 1 and 2, slightly separated medially on 3 and 4, more minute and vague on 5, and becoming rather sparse and indefinite on 6, apical margins rather broadly impressed and impunctate, more or less brownish-hyaline, that of tergum 6. with a shallow, median emargination, 7 quite broad but with a deep, rounded, median emargination; sternum 2 broadly rounded apically, covering much of the following sterna, 3 with a very deep, triangular, median emargination which is to a considerable degree filled with fine, converging setae (fig. 33), median area of 4 subtruncate (fig. 34), 6 with a somewhat rounded, median, apical lobe which has a very slight median emargination; genital armature resembling that of 0. virga (fig. 35), with broad, subtruncate penis valves, but tips of gonocoxites not so narrow and elongate (much as in sandhouseae, fig. 31).
DISTRIBUTION — This is holarctic and has been found in eastern North America in Labrador, Quebec, the New England states and Wisconsin, from May to July.
FLOWER RECORDS — Rubus, Salix and Vaccinium.