Reprinted with permission from: Mitchell, T.B. 1962 Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 152.
Megachile brevis brevis
FEMALE�Length 9-12 mm.; black, including tegulae and legs, spurs yellowish; eyes slightly convergent below; clypeal margin nearly straight, median third narrowly shining and impunctate; mandibles 4-dentate, with bevelled edges between 2nd and 3rd, 3rd and 4th (fig. 38); lateral ocelli subequally distant from eyes and margin of vertex; cheeks slightly narrower than eyes; punctures deep, distinct and rather coarse, well separated between eyes and ocelli and on clypeus and supraclypeal area medially, closer between ocelli, across upper part of face, below ocelli and on lateral margins of clypeus, finer and more shallow and vague on cheeks; pubescence white, rather copious around a4ennae and inner orbits on cheeks, especially below, and on thorax laterally and posteriorly, largely black on vertex, scutum and scutellum; punctures of scutum close, moderately coarse, slighty separated across disc medially, those on axillae and scutellum somewhat closer and finer, shallow and rather densely crowded on pleura, propodeum somewhat smoother, punctures very fine, shallow and indistinct; mid and hind basitarsi nearly as broad as their tibiae; tegulae minutely and rather closely punctate; wings sub-hyaline, becoming faintly clouded along apical margin, veins piceous; abdominal terga 2-5 shallowly grooved or depressed toward basal margin, apical margins more abruptly depressed laterally, rims very narrowly yellowish-hyaline; basal tergum with copious, elongate, erect, whitish pubescence, discal pubescence of tergum 2 somewhat shorter but entirely whitish, that on 3-5 black in part, 2-5 with entire, whitish, apical fasciae; punctures close and fine on terga 1 and 2, somewhat more widely separated on 3-5, 6 distinctly concave in profile, with rather abundant, erect pubescence, blackish toward base becoming pale apically; sternum 6 well covered with scopal hairs, these largely pale, apical margin with a dense fringe of short, more fuscous hairs, scopa yellowish-white, sternal plates quite coarsely and closely punctate, narrowly yellowish-hyaline apically.
MALE�Length 7-9 mm.; black, including tegulae and legs, spurs testaceous; eyes slightly convergent below; cheeks somewhat narrower than eyes; clypeal margin obscured by a dense, elongate, white fringe, nearly straight, but median area very slightly in- curved; mandibles conspicuously 3-dentate, with an acute, sub-basal inferior process; apical segment of flagellum narrow and elongate; lateral ocelli very slightly nearer eyes than to margin of vertex; cheeks slightly narrower than eyes; punctures deep and distinct, but not very coarse, rather close across vertex, and between eyes and ocelli, becoming very fine, close and obscure on the more shining
cheeks, rather coarse and quite closely crowded below ocelli, but becoming minute and densely crowded on supraclypeal area and sides of face beneath pubescence, but upper half of clypeus with distinct, rather coarse and quite close punctures evident, these becoming minute and densely crowded apically where surface is obscured by pubescence; pubescence largely pale on head and thorax, with only a few more yellowish hairs interspersed on vertex and scutum; pubescence quite copious and erect around antennae, on sides of face and on clypeus apically, elongate and quite copious on cheeks below and on thorax laterally and posteriorly, somewhat thinner but erect and quite copious on vertex and dorsum of thorax; punctures quite deep, distinct and close over most of scutum and scutellum, relatively fine, slightly separated along mid-line of scutellum, quite densely crowded and fine on pleura, propodeum somewhat more shining; front coxal spines well developed but rather short, subacute, quite densely long pubescent; mid tibial spurs well developed; all basitarsi much narrower than their tibiae; tegulae minutely and rather closely punctate; wings subhyaline, veins brownish to piceous; abdominal terga 2-4 quite deeply depressed toward basal margin, apical margins narrowly and abruptly depressed, more deeply so laterally except on 4, margins narrowly yellowish-hyaline, and yellowish or whitish fasciate, discal pubescence copious and erect on terga 1 and 2, somewhat shorter but erect and rather conspicuous on 3-5; terga 1 and 2 very closely and finely punctate, punctures more distinctly separated and somewhat coarser on 3 and 4, quite coarse and close over 5 which has a thin, basal yellowish or whitish, tomentose band and a dense, apical, entire fascia of the same color; tergum 6 whitish tomentose in large part dorsally, carina with a small, median emargination, which is obscured by the irregular, more lateral crenulations, median teeth of apical margin nearer lateral teeth than to each other; sterna 1-4 exposed, apical margins depressed and yellowish-hyaline, conspicuously fringed with elongate, pale hairs, punctures close and fine on 1 and 2, somewhat coarser and more widely separated on 3 and 4; setose area of sternum 5 extensive (fig. 36), exceedingly minute; sternum 6 with numerous, scattered, robust setae on each side, apical lobe broad and short, not acutely angulate; gonocoxities constricted above base, compressed apically, the apex acute (fig. 37).
DISTRIBUTION�This is one of the most widely occurring species of bees in North America, ranging from the Atlantic to the Pacific, both in the United States and in southern Canada, throughout the season.
FLOWER RECORDS�Asclepias, Astragalus, Bidens, Chrysanthemum, Erigeron, Fagopyrum, Gossypium, Haplopap pus, Helianthus, Hieraceum, Hypericum, Kuhnistera, Lupinus, Medicago, Melilotus, Ocimum, Oenothera, Phctseolus, Polygonum, Psoralioides, Rhus, Rubus, Salvia, Solidago, Stachys, Suriana, Tephrosia, Trifolium and Vicia. The following additional genera are listed by Robertson (1929): Abutilon, Acerates, Amorpha, Apios, Aster, Ble phiha, Boltonia, Brauneria, Cam panula, Cassia, Ceano thus, Cephalanthus, Cicuta, Coreopsis, Cornus, Cynoglossum, Desmodium, Dianthera, Erechthites, Eryngium, Eupatorium, Gerardia, Helenium, Hehiopsis, Hibiscus, Hydrophyhlum, Impatiens, Krigia, Lactuca, Lepachys, Lespedeza, Lineria, Lippia, Lobelia, Ludvigia, Lyco pus, Lythrum, Marrubium, Nepeta, Pent stemon, Petalostemum, Physostegia, Psoralea, Pycnanthemum, Rosa, Rudbeckia, Rue hlia, Sabatia, Sagittaria, �Scutehlaria, Silphium, Stropho styles, Teucrium, Tradescantia, Verbena and Verbesina.
Megachile brevis pseudobrevis
Although this has been accorded specific status by Michener (1947), the occurrance intergrading forms in the southeast convinces us that it is more properly to be considered subspecific in rank. It agrees with typical brevis in all structural details, the chief difference being that in the female the scopa of sternum 6 is black, and the black pubescence is more conspicuous on the vertex, scutum and the more apical, abdominal terga, including tergum 6. In the male, the discal pubescence of terga 3-5 to a considerable degree black. In typical brevis the scopa is white on sternum 6, with only the apical, dense fringe of hairs all dark, and in the male the pubescence the abdomen is almost entirely pale. Specimens collected in the Northeast usually fit the description of typical brevis, while in the Southeast, especially along the Coastal Plain and into Florida, pseudobrevis is the prevalent form.
DISTRIBUTION�Florida to North Carolina; April to October, in Florida, March to December.
FLOWER RECORDS�A fzelia, Chrysopsis, Erigeron, Galactia, Helenium, Hehianthus, Lupinus, Melilotus, Opuntia, Polygonum, Rhus, Rubus, Sohidago, Suriana, Trilisa and Vaccinium. Michener (1947) records this subspecies on Gaylussacia.
Megachile (Litomegachile) brevis Say, 1837
Extracted from: Sheffield C. S., et al (2011). Leaf cutter and Mason Bees of the Genus Megachile Latreille (Hymenoptera; Megachilidae) in Canada and Alaska. Canadian Journal of Arthropod Identification No. 18
Megachile brevis Say, 1837. Boston J. Nat. Hist. 1: 407 (♂, ♀).
Megachile lanuginosa Smith, 1853. Cat. Hym. Brit. Mus. 1: 190 (♀, ♂).
?Megachile nupta Cresson, 1872. Trans. Amer. Entomol. Soc. 4: 268 (♀).
Megachile perbrevis Cresson, 1878. Trans. Amer. Entomol. Soc. 7: 127 (♂).
Diagnosis. The female of M. brevis can be recognized by the combination of 4-dentate mandibles with the emargination between inner and 3rd teeth being approximately semicircular (i.e., its greatest depth subequally distant between the two teeth), T6 being distinctly concave in lateral view, and S6 with scopal hairs mostly pale. They are most similar to M. coquilletti and M. onobrychidis. Females of M. coquilletti and M. onobrychidis have the scopa on S6 entirely black. The male of M. brevis can be recognized by the combination of simple and dark front tarsi, front coxa possessing a small spine, 3-dentate mandibles, T5 with a white apical fascia, T6 with transverse carina weakly emarginate medially, with the surface above carina with white tomentum dense and conspicuous medially, concealing most of the surface beneath. They are most similar to M. coquilletti and M. onobrychidis. Males of M. coquilletti have yellow front tarsomeres 2-4. Males of M. onobrychidis have the surface of T6 above the carina largely visible, with very little white tomentum.
FEMALE: Length 9-12 mm.
Head. 1) compound eyes slightly convergent below; lateral ocelli subequally distant from eyes and margin of vertex, 2) clypeal margin nearly straight, median third narrowly shining and impunctate, 3) mandibles 4-dentate, with an incomplete cutting edge between 2nd and 3rd teeth, complete between the 3rd and 4th teeth (Plate 1, Figure M7), 4) gena slightly narrower than compound eye (3:4), 5) punctures deep, distinct and rather coarse, more separated between eyes and ocelli, on clypeus and supraclypeal area medially, closer between ocelli, across upper part of face and frons, and on lateral margins of clypeus, finer and more shallow and vague on gena, 6) pubescence white, rather copious around antennae and inner orbits, on gena, especially below, largely black on vertex, 7) F1 very slightly longer than broad, subequal in length to pedicel and to remaining flagellomeres, apical flagellomere more elongate (3:7).
Mesosoma. 1) pubescence white, rather copious laterally and posteriorly, mesoscutum with interspersed black pubescence, less so on scutellum, 2) punctures of mesoscutum close, moderately coarse, slightly separated across disc medially, those on axilla and scutellum somewhat closer and finer, shallow and rather densely crowded on pleura, propodeum somewhat smoother, punctures very fine, shallow and indistinct, triangle dull and impunctate, 3) mid and hind basitarsi nearly as broad as their tibiae, spurs yellowish, 4) tegula minutely and rather closely punctate, 5) wings subhyaline, becoming faintly clouded along apical margin, veins black.
Metasoma. 1) T2-T5 shallowly grooved and depressed toward basal margin, weakly carinate, apical margins more abruptly depressed laterally, rims very narrowly yellowish-hyaline; T1 with copious, elongate, erect, whitish pubescence, discal pubescence of T2 somewhat shorter and entirely whitish, that on T3-T5 black in part just basal to apical fasciae, T2-T5 with entire, whitish, apical fasciae; punctures close and fine on T1 and T2, somewhat more widely separated on T3-T5, dense on T6; T6 distinctly concave in profile, with rather abundant, erect pubescence, blackish toward base becoming pale apically, 2) scopa yellowish-white, including S6, which is well covered with scopal hairs, apical margin of S6 with a dense fringe of short, brownish hairs; sterna quite coarsely and closely punctate, narrowly yellowish-hyaline apically.
MALE: Length 7-9 mm.
Head. 1) compound eyes slightly convergent below; lateral ocelli very slightly nearer eyes than margin of vertex (5:6), 2) clypeal margin nearly straight, but median area impunctate and very slightly incurved, 3) mandibles 3-dentate, lower process acute, subbasal in position, 4) gena narrower than compound eye (5:8), 5) punctures deep and distinct, but not very coarse, rather close across vertex, more separated (≤ 1 pd) laterally and between eyes and ocelli, becoming very fine, close and obscure on the more shining gena, rather coarse and quite closely crowded on frons, but becoming minute and densely crowded on supraclypeal and paraocular areas beneath pubescence, upper half of clypeus with distinct, rather coarse and slightly separated punctures evident, these becoming minute and densely crowded apically where surface is obscured by pubescence, 6) pubescence largely pale on head, pubescence quite copious and erect around antennae, on paraocular area, and on clypeus apically, elongate and quite copious on gena below, somewhat sparser but erect on vertex, 7) F1 about as long as broad, and slightly shorter than pedicel, remaining flagellomeres longer than broad (3:2), apical flagellomere more elongate, twice as long as broad.
Mesosoma. 1) pubescence entirely pale, elongate and quite copious laterally and posteriorly, somewhat sparser but erect dorsally, 2) punctures quite deep, distinct and close over most of mesoscutum and scutellum, relatively fine, slightly separated along mid-line of scutellum, quite densely crowded and fine on pleura, propodeum somewhat more shining, triangle dull and impunctate, 3) front coxal spine well developed but rather short, subacute, quite densely long pubescent; mid tibial spur well developed; all basitarsi much narrower than their tibiae, spurs yellowish-brown, 4) tegula minutely and rather closely punctate, 5) wings subhyaline, veins brownish-black.
Metasoma. 1) T2-T5 quite deeply depressed toward basal margin, with a distinct carinate rim, apical margins narrowly and abruptly depressed, more deeply so laterally except on T4, margins narrowly yellowish-hyaline, with yellowish-white fasciae; sparse pale tomentum basally on T2-T5, pale discal pubescence copious and erect on T1 and T2, somewhat shorter but erect and rather conspicuous on T3-T5; T1 and T2 very closely and finely punctate, punctures more distinctly separated and somewhat coarser on T3 and T4, quite coarse and close over T5, T6 whitish tomentose in large part dorsally, carina with a small, median emargination that is obscured by the irregular, more lateral crenulations, median teeth of apical margin nearer lateral teeth than to each other, 2) S1-S4 exposed, apical margins depressed and yellowish-hyaline, conspicuously fringed with elongate, pale hairs, interrupted medially on S4, punctures close and fine on S1 and S2, somewhat coarser and more widely separated on S3 and S4.
Genitalia. Plate 2, Figure G7.
Discussion. This species is very similar to M. coquilletti and M. onobrychidis, but in Canada, the latter two are recorded only from BC, whereas M. brevis is widespread from NB west to southern BC. Megachile onobrychidis is often considered a subspecies of M. brevis, to which it is closely related, but is recognized here as a valid species based on 5.47% sequence divergence in CO1 and subtle but consistent morphological differences outlined above. Though not recorded from Canada, divergence levels in CO1 also indicate that M. pseudobrevis Say from the southeastern USA is a distinct species, as first suggested by Michener (1947), a view supported by other authors (e.g., Hall and Ascher 2011). Therefore, it is not included as a synonym of M. brevis. This species nests in hollow plant stems and in soil.
Distribution. Widespread in southern Canada from NB-BC. Ivanochko (1979) reported a specimen from NS, but this could not be found. Extensive surveys of bees (see Sheffield 2006; Sheffield et al. 2003; 2008) failed to document its presence in that province.
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