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Megachile pruina, f, charlotte county, fl, face ---.
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Megachile pruina, f, charlotte county, fl, side ---.
© NC Agriculture State Experiment Station Technical Bulletin Number 152, T. B. Mitchell, 1962
Megachile pruina, female, mandibles
Note: Mitchell mentions that M. pruina females have a complete cutting edge present in the mandibles between the second and third tooth, while this is true in some individuals others clearly only have a partial cutting edge, though it may nearly fill the gap between the teeth. Other features include bare central S6, black hairs only on S6, black hairs in center of clypeus in unworn individuals, regular non-overlapping white appressed hairs largely cover T6, very large coastal species.
Reprinted with permission from: Mitchell, T.B. 1962 Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 152.
Megachile pruina pruina
FEMALE—Length 12-13 mm.; entirely black, including tegulae and legs, spurs pale yellow; eyes very slightly convergent below; clypeal margin straight; mandibles quite broad apically, 4-dentate, with bevelled edges between 2nd, 3rd and 4th teeth (fig. 53) lateral ocelli very slightly near margin of vertex than to eyes; cheeks subequal to eyes in width; vertex somewhat shining, punctures quite deep and distinct, rather coarse along margin, and between and behind ocelli, becoming somewhat finer and more sparse between eyes and ocelli, close on cheeks, becoming almost rugose below; face below anterior ocellus rather coarsely rugoso-punctate, becoming very finely and densely so laterally beneath dense pubescence, supraclypeal area with some shining spaces medially, but densely punctate laterally and above, clypeus with a somewhat more lightly punctured median line, closely and densely punctate on each side; pubescence white, quite dense and elongate around antennae and along inner orbits, rather sparse, sub- erect and largely pale on clypeus, a few black hairs intermixed with the white between antennae, largely black on vertex, rather short and pale on cheeks above, becoming somewhat more elongate below; thorax white pubescent laterally and posteriorly, scutum and scutellum with rather short but erect, rather conspicuous, black pubescence, scutum narrowly pale pubescent anteriorly, and scutello-mesothoracic suture with, a •very narrow line of pale tomentiim; scutum and scutellum some-what shining, punctures rather deep and disdens,
tinct, fine over most of scutum, slightly sepreopsis,
arated over the broad, median area, slightly
more coarse and sparse medially on scutellum,
but becoming much closer laterally axillae
with fine and close punctures; pleura rather
dull, punctures rather coarse and contiguous below, becoming finer and densely crowded above; propodeum rather smooth, only obscurely and shallowly punctate laterally, posterior face with rather close, shallow and minute punctures; basitarsi slightly narrower and considerably shorter than their respective tibiae, mid basitarsus with conspicuous, fuscous pubescence on outer face; tegulae minutely and closely punctate; wings subhyaline, becoming somewhat clouded apically, veins brownish-piceous; abdominal terga 2 and 3 with transverse, complete but rather shallow, sub-basal grooves, basal margins of these grooves distinct but hardly carinate, terga 4 and 5 shallowly depressed toward base, but basal margin indistinct; apical margins of terga narrowly depressed only toward sides, narrowly but quite densely white fasciate; basal tergum with rather copious, elongate, entirely pale pubescence, discal pubescence of following terga more or less erect, short, completely black; punctures of terga rather fine and close, uniformly minute and close on tergum 2, becoming slightly coarser and somewhat more definitely separated apically, tergum 6 straight in profile, with a few sub- erect, black hairs evident, these becoming erect and more conspicuous at sides in dorsal view, surface largely covered with appressed, pale tomentum which obscures surface, the minute and densely crowded punctures evident only toward sides; sternum 6 largely bare except for a basal fringe of scopal hairs, apical margin slightly produced beyond the subapical fringe of short, dark setae; scopa otherwise white, with a few black hairs at extreme sides of sterna 4 and 5, and across base of 6; sternal plates quite closely, rather finely punctate, apical margins narrowly yellowishhyaline, sternal fasciae not present.
MALE—Length 11-12 mm.; black, the front legs and mid and hind tarsi in considerable part yellow, tegulae black with brownish and yellowish blotches, tibial spurs yellow; eyes very slightly convergent below; median portion of clypeal margin very slightly produced; mandibles 4-dentate, with a rather dense tuft of short, whitish hairs on outer side as seen from above (fig. 53), inferior process basal in position, subacute apically, lower margin of mandible with a submedian, distinct, apically directed angle; apical segment of flagellum slender and elongate; lateral ocelli subequally distant from eyes and margin of vertex; cheeks subequal to eyes in width, lower margin slightly excavated and angulate, rather finely but copiously pale pubescent; vertex shining, punctures quite deep and distinct, rather close and coarse medially, becoming somewhat more fine and sparse laterally, rather close but shallow and obscure on cheeks, becoming very
fine and densely crowded below; surface below ocelli and on clypeus rather finely rugosopunctate; pubescence yellowish-white, copious and rather dense on face around and below antennae, thin and whitish on cheeks medially, more yellowish or fuscous, thin and erect on vertex; pubescence rather thin but somewhat copious and elongate on thorax laterally and posteriorly, scutum with largely erect, short, fuscous hairs, these more or less whitish anteriorly, scutellum with a few, erect, fuscous hairs in the generally pale pubescence, the scutellum-mesothoracic suture very obscurely pale tomentose, and a small, white tuft just back of each tegula; scutum and scutellum rather uniformly, closely, deeply and rather finely punctate, punctures somewhat more distinct medially, slightly finer on scutellum medially, but becoming slightly coarser on axillae; pleura rather dull beneath the pubescence, punctures rather coarse but very close, propodeum somewhat more shining, punctures shallow and vague but rather numerous, posterior face somewhat more shining, punctures numerous but minute and rather obscure; front coxal spines long and erect, narrowly spatulate, with rounded tips, coxal surfaces rather smooth and bare anterior to the spine, without red bristles, becoming rather densely white pubescent laterally; front tarsi entirely yellow, basitarsus somewhat excavated anteriorly, gradually dilated to the broad tip, base slightly narrower than its tibia, following segments successively shorter and narrower, posterior fringe rather broad, white tipped with brownish beneath; front tibia piceous except for the narrow, yellowish apex, inner and anterior surfaces more testaceous; apical portion of posterior face of front femora piceous with a broadly impunctate, bright yellow, ventral rim, carinate dorsally, upper surface otherwise bright yellow or testaceous, anterior surface largely testaceous; lower apical angle of mid tibia prolonged to form a spur-like projection, spur entirely lacking; mid and hind tarsi yellow anteriorly, posterior margin narrowly fuscous, mid tarsi with a thin posterior fringe of elongate, pale hairs, hind tarsi with an anterior fringe of elongate hairs; tegulae minutely but very closely and distinctly punctate; wings rather lightly infuscated, veins brownish to piceous; abdominal terga 2-5 shallowly depressed across base, basal margins of these depressions quite distinct, more or less carinate, apical margins of the terga conspicuously depressed laterally; basal tergum with rather copious, erect, elongate, entirely pale pubescence, 2-4 with short, black, erect, discal pubescence, that on 5 blackish toward base but becoming pale toward apical margin; punctures fine and quite close on the more basal terga, becoming somewhat more distinct and more widely separated on 3 and4, rather coarse and irregular on 5; tergum 6 vertical, surface above carina very finely and densely rugose, with scattered, fine and irregular nodules, the carina rather low but distinct, with a rather narrow, rounded, median emargination, median teeth of apical margin evi dent only as low carinae which are considerably nearer the very small but acute lateral teeth than to each other; tergum 7 transverse, largely hidden, very slightly angulate medially; sterna 1-4 exposed, punctures very fine and rather close on the more basal segments, becoming somewhat more sparse apically, apical margins rather broadly depressed, abruptly hyaline except on 4; setose area of sternum 5 restricted in area, its apical margin with an abrupt emargination in which is located an elongate, tapering, acute median lobe, a rather elongate, wing-like lobe on each side, setae very fine, those along apical margin elongate, especially on each side where they are curved and abruptly flexed apically (fig. 54); setose area of sternum 6 more restricted in area, forming a somewhat oblique, transverse line, slightly separated medially, the more lateral setae robust, very long and directed medially, apical lobe elongate, very narrow basally, broadened apically, lateral angles narrowly produced and acute; gonocoxites of genital armature gradually narrowed from base to near the tip, bilobate apically, dorsal lobe flexed inwardly, its oblique, apical margin shallowly excavated, ventral lobe extremely robust, more or less rounded, with its ventral surface deeply excavated (figs. 50 and 55).
DISTRIBUTION — North Carolina to Florida and Texas, March to October in Florida, June to September elsewhere.
FLOWER RECORDS—Asclepias, Crotalana, Cuscuta, Gaillardia, Helianthus, Ocimum, Rhus and Strophostyles. Graenicher (1930?) records it on Croton, Dalbergia, Galactia, Melanthera and Vernonia.
The subspecific designation is used here for this typical form of pruina because of the occurrence of another form, nigropinguis Mitchell in Texas.
Updated: 2019-10-14 01:37:06 gmt