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Megachile pugnata Say, 1837
Megachile scrobiculata Smith, 1853; Megachile bucephala Smith, 1853; Megachile disparilis Cresson, 1872; Megachile lucrosa Cresson, 1872; Gnathocera cephalica Provancher, 1882; Ceratias_homonym pugnata (Say, 1837); Megachile temporalis_homonym Friese, 1903, female not male; Sayapis pugnata (Say, 1837); Megachile pugnata pomonae Cockerell, 1916; Megachile (Sayapis) pugnata pomonae Cockerell, 1916, valid subspecies

Life   Insecta   Hymenoptera   Apoidea   Megachilidae   Megachile
Subgenus: Sayapis

Megachile pugnata, female, face
Smithsonian Institution, Entomology Department · 9
Megachile pugnata, female, face

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Megachile pugnata, female, side
Smithsonian Institution, Entomology Department · 9
Megachile pugnata, female, side
Megachile pugnata, female, top
Smithsonian Institution, Entomology Department · 9
Megachile pugnata, female, top

Megachile pugnata, female, wing
Smithsonian Institution, Entomology Department · 9
Megachile pugnata, female, wing
Megachile pugnata FEM comp
© Copyright Laurence Packer 2014 · 7
Megachile pugnata FEM comp

Megachile pugnata MALE comp
© Copyright Laurence Packer 2014 · 7
Megachile pugnata MALE comp
Megachile pugnata, f, face, National Arboretum, DC ---.. ZS PMax UDR
© Copyright source/photographer · 5
Megachile pugnata, f, face, National Arboretum, DC ---.. ZS PMax UDR

Megachile pugnata, f, side, National Arboretum, DC ---.. ZS PMax UDR
© Copyright source/photographer · 5
Megachile pugnata, f, side, National Arboretum, DC ---.. ZS PMax UDR
Megachile pugnata, Female mandible
Robert Snyder, Pennsylvania State Univeristy · 1
Megachile pugnata, Female mandible

Megachile pugnata
Hartmut Wisch · 1
Megachile pugnata
Megachile pugnata, side
Hartmut Wisch · 1
Megachile pugnata, side

Megachile pugnata, Barcode of Life Data Systems
Barcode of Life Data Systems · 1
Megachile pugnata, Barcode of Life Data Systems
Megachile pugnata, female, headprofile
© Contribution Department of Entomology North Carolina State University, T. B. Mitchell, 1980 · 1
Megachile pugnata, female, headprofile

Megachile pugnata, female, face
© Stephanie Kolski and Natalie Allen · 1
Megachile pugnata, female, face
Megachile pugnata, female, side
© Stephanie Kolski and Natalie Allen · 1
Megachile pugnata, female, side
Overview
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.; abdomen elongate and parallel-sided; entirely black, including tegulae and legs; eyes slightly divergent below; clypeus extremely short and very much thickened apically, the outer face little any longer medially than the thickened edge, margin with a rather broad, median, truncate protuberance and a pair of more lateral tuberdes; mandibles very much broadened apically, obscurely 5-dentate, 4th tooth very low, a small bevelled edge between 2nd and 3rd (fig. 56); lateral ocelli very much nearer eyes than to margin of vertex; width of cheeks nearly twice that of eyes, with a conspicuous, flattened, subtriangular process opposite lower end of eye; vertex rather dull, punctures very fine and close, becoming relatively coarse and more separated on cheeks above, closer and irregular below, but lower surface broadly shining and impunctate; face below ocelli densely rugoso-punctate, conspicuously protuberant between antennae, punctures of supraclypeal area quite coarse and distinct but very close, clypeus with very fine, densely crowded punctures medially, these becoming coarse and more distinct laterally; pubescence white on face and cheeks, short but rather dense between antennae and eyes, more yellowish on clypeus and on lower surface of cheeks, very short and sparse on cheeks above, vertex with quite conspicuous, erect, black pubescence which does not hide surface; thorax with rather short, quite dense, white pubescence laterally and posteriorly, scutum with largely blackish, erect pubescence, this becoming pale across anterior margin, scutellum with somewhat more elongate, black hairs, with a few paler hairs toward posterior margin; scutum finely and closely punctate, punctures slightly separated only in center, those of scutelluni and axillae uniformly very fine and close; pleura dull beneath the pubescence, very closely punctate, more coarsely so below and finer above; lateral faces of propodeum somewhat smoother but dull and quite densely pubescent, posterior face rather dull, punctures close but exceedingly minute and vague; all basitarsi somewhat shorter and narrower than their tibiae; tegulae with exceedingly minute and rather close punctures; wings subhyaline basally, becoming somewhat infuscated apically, veins brownish to piceous; abdominal terga 2-5 more or less deeply grooved across base, basal margin of grooves subcarinate, apical margin of terga rather deeply depressed, with dense, entire, whitish fasciae; pubescence of tergum 1 whitish, rather copious and elongate, becoming dense at extreme sides, with some shorter, more apical, fuscous hairs; discal pubescence of following terga very short, erect and quite dense, entirely black; punctures of terga very fine and close throughout; apical margin of tergum 6 rather abruptly upturned, rather narrowly rounded, surface very densely and finely punctate, pubescence suberect and entirely black; sternum 6 subtriangular, with narrow apex, the apex slightly emarginate, surface uniformly covered with short, blackish scopal hairs; scopa otherwise pale yellow, the more basal sterna finely and closely punctate, punctures becoming more coarse and sparse on the more apical sterna, apical margins somewhat depressed, distinctly yellowishhyaline; sternal fasciae not evident.

MALE—Length 11-13 mm.; black, tegulae brownish-testaceous, front tarsi, and mid and hind spurs yellow; eyes subparallel; clypeal margin beneath beard nearly straight, with very shallow, median and sublateral emarginate areas; mandibles quite slender, obscurely 3-dentate, inferior process submedian, triangularly acute and densely pubescent; apical segment of flagellum very slightly dilated; lateral ocelli subequally distant from eyes and margin of vertex; cheeks subequal to eyes in width, with a shining, impunctate, concave area below, lower margin of this produced to form a conspicuous and rather slender process just below base of mandible; vertex and cheeks rather dull, punctures very fine and densely crowded, face dull, densely and finely rugosopunctate beneath dense pubescence; face with copious, erect, yellowish-white pubescence that largely obscures surface, cheeks white pubescent, this rather short •above, becoming dense and elongate below, vertex with erect and elongate yellowish hairs intermixed with shorter and more fuscous hairs; thorax with rather short, dense, white pubescence laterally and posteriorly, scutum with quite copious, erect and elongate fuscous hairs, becoming whitish anteriorly, scutellum with largely whitish pubescence; punctures of scutum fine and close, slightly separated only in center, densely crowded otherwise, those of scutellum and axillae uniformly fine and close; pleura dull, punctures rather shallow but very close, becoming densely crowded above; lateral faces of propodeum somewhat smoother, punctures shallow, very fine and close, posterior face rather dull, punctures quite close but exceedingly minute; front coxal spines very slender and elongate, anterior surface of coxae bare and somewhat shining, with a patch of 4 or 5 elongate, reddish bristles just before base spines; mid tibial spurs well developed; front tarsi bright yellow, basitarsus enormously expanded anteriorly and apically, very deeply excavated, inner basal margin of excavation with a short fringe of fuscous hairs, otherwise hairs entirely pale yellowish, the basitarsal scale reaching fully to the tip of segment 2, the more posterior part of 2 much shorter than that of 1 and 3, posterior fringe pale yellow, quite dense and elongate, more or less brownish beneath; outer surface of front tibiae and posterior surface of front femora piceous, other surfaces more or less yellowish or testaceous; mid and hind basitarsi slender and simple, largely dark, the more apical tarsal segments becoming more testaceous or brownish; tegulae shining, punctures exceedingly minute but rather close; wings subhyaline, veins brownish; abdominal terga 2-5 rather shallowly depressed across base, basal margin of these distinct but not conspicuously can- nate, apical margin of terga narrowly depressed on the more basal segments, becoming quite broad, more or less yellowish-hyaline and narrowly white fasciate on 4, these fasciae quite dense and conspicuous on 4 and 5; terga 1 and 2 with copious, elongate, pale pubescence, but 2 also with some shorter, more apical, fuscous pubescence, discal pubescence of 3 and 4 short, erect, quite copious and entirely black, that on 5 largely black, but more erect and elongate; punctures of terga very fine and close throughout; dorsal surface of tergum vertical, very densely and finely rugoso-punctate, carina rather short but distinct, with small, more or less rounded, median emargination, median teeth of apical margin very low, carinate, much closer to lateral angles than to each other, but these lateral angles not at all spinose; tergum 7 rather robust, obscurely angulate medially, but not produced; sterna 1-4 exposed, rather dull but very minutely and regularly punctate, punctures quite close but not crowded, apical margin depressed and yellowish-hyaline, that of 4 very slightly in- curved across median area; setose area ot sternum 5 broad and extensive, the setae curved and simple, apical margin slightly angulate medially (fig. 57); setose areas sternum 6 slightly separated, bilobate, the more basal lobes with large, closely set setae, the more apical pair with an apical fringe of 4 or 5 large, curved setae, apical marginal lobe extensive, somewhat narrowed and rounded apically; gonocoxites much narrowed above base, gradually dilated and obliquely compressed to the rounded tips, finely setose on inner surface (fig. 58).

DISTRIBUTION—The Pacific Coast to Quebec and the New England states, south to Texas and Georgia, June to September.

FLOWER RECORDS—Arctium, Aster, Brauneria, Carduus, Chrysanthemum, Engeron, Helianthus, Melilotus, Rudbeckia, Taraxacum, Trifolium, Verbena and Vernonia. Robertson (1929) records pugnata on the following: Asciepias, Blephilia, Cicuta Cirsium, Coreopsis, Dianthera, Lepachys, Nepeta, Silphium and Verbesina. The subspecific designation of this typical form of pugnata is made necessary by the occurrence of another form, pomonae Cockerell, in the Southwest.

Extracted from C. S. Sheffield 2011. Canadian Journal of Arthropod Identification No. 18 (November 2011)

Megachile (Sayapis) pugnata Say, 1837

Megachile pugnatus Say, 1837. Boston Jour. Nat. Hist. 1: 408 (♂, ♀). Megachile scrobiculata Smith, 1853. Cat. Hym. Brit. Mus. 1: 191 (♂). Megachile bucephala Smith, 1853. Cat. Hym. Brit. Mus. 1: 193 (♀). Megachile disparilis Cresson, 1872. Trans. Amer. Entomol. Soc. 4: 264 (♂). Megachile lucrosa Cresson, 1872. Trans. Amer. Entomol. Soc. 4: 267 (♀). Gnathocera cephalica Provancher, 1882. Nat. Canad. 13: 233 (♀). Megachile temporalis Friese, 1903. Ztschr. System. Hym. Dipt. 3: 247 (♀ only). Megachile pugnata pomonae Cockerell, 1916. Ann. Mag. Nat. Hist (8) 17: 278 (♀).

Diagnosis. The female of M. pugnata is distinct and can be recognized by the prominent robust process on the lower edge of the gena. The male of M. pugnata can be recognized by the combination of 3-dentate mandibles, T5 with white apical fascia, front basitarsus with brush of short, dark bristles reduced, not extending beyond its basal third, and apical third of boat-shaped dilation entirely covered on the outer side with dense appressed hairs. They are most similar to M. fidelis and M. mellitarsis. Males of M. mellitarsis have T5 without white apical fascia, and the front basitarsus with boat-shaped dilation elongated apically and extending to apex of 3rd tarsomere. Males of M. fidelis have the front basitarsus with brush of dark bristles extending nearly to apex, with boat-shaped dilation mostly bare and polished in apical third.

FEMALE: Length 12-18 mm.

Head. 1) compound eyes slightly divergent below; lateral ocelli very much nearer eyes than margin of vertex (5:7), 2) clypeus extremely short and very much thickened apically, about as long or only slightly longer medially than the thickened apical edge, margin with a rather broad, median, truncate protuberance and a pair of more lateral tubercles, 3) mandibles very broad apically, obscurely 5-dentate, the 4th tooth very low and rounded, not acute like remaining teeth, with a small incomplete cutting edge between 2nd and 3rd teeth (Plate 1, Figure 29), 4) gena nearly twice the width of compound eye (8:5), with a conspicuous, flattened, subtriangular process opposite lower end of eye, 5) vertex rather dull, punctures very fine and close, becoming relatively coarse and more separated on gena above, larger and more irregular below, lower surface of gena apical to process broadly shining and impunctate; frons densely rugosopunctate, conspicuously protuberant between antennae, punctures of supraclypeal area quite coarse and distinct but very close, with a small impunctate area along apical edge; clypeus with very fine, densely crowded punctures medially, becoming coarse and more distinct laterally, shiny and impunctate below margin, 6) pubescence white on face and gena, short but rather dense on paraocular area, more yellowish on clypeus and on lower surface of gena, very short and sparse on gena above, vertex with quite conspicuous, erect, black pubescence that does not hide surface, 7) F1 quadrate, subequal in length to pedicel and F2, remaining flagellomeres slightly longer than broad (3:2), apical flagellomere more elongate (4:2.5).

Mesosoma. 1) pubescence rather short, quite dense, white laterally and posteriorly, pubescence of mesoscutum largely black, sparse and erect, becoming pale across anterior margin, scutellum with somewhat more elongate, black hairs, with a few paler hairs toward posterior margin, 2) mesoscutum finely and closely punctate, punctures slightly separated only in centre, those of scutellum and axilla uniformly very fine and close; pleura dull, very closely punctate, more coarsely so below and finer above; propodeum somewhat smoother but dull and quite densely pubescent, punctures close but minute and vague, triangle dull and impunctate, 3) all basitarsi somewhat shorter and narrower than their tibiae, apical segments of legs somewhat reddish-brown, 4) tegula almost impunctate, a few minute and rather close punctures anteriorly, 5) wings subhyaline basally, becoming somewhat infuscated apically, veins brownish-black.

Metasoma. 1) elongate and parallel-sided, T2-T4 more or less deeply grooved across base, less so on T5, basal margin of grooves carinate, apical margin of terga rather deeply depressed, with dense, entire, whitish fasciae; pubescence of T1 whitish, rather copious and elongate, becoming dense at sides, with some shorter, more apical, brown hairs; discal pubescence T2-T6 very short, erect and quite dense, entirely black; punctures of terga very fine and close throughout; apical margin of T6 rather abruptly upturned, rather narrowly rounded, surface very densely and finely punctate, pubescence suberect and entirely black, 2) S6 subtriangular, with narrow slightly emarginated apex, S6 uniformly covered with short, blackish scopal hairs; scopa otherwise pale yellow, the more basal sterna finely and closely punctate, punctures becoming more coarse and sparse on the more apical sterna, apical margins somewhat depressed, distinctly yellowish-hyaline.

MALE: Length 11-13 mm.

Head. 1) compound eyes subparallel; lateral ocelli subequally distant from eyes and margin of vertex, 2) clypeal margin beneath pubescence nearly straight, with very shallow, median and sublateral emarginate areas, 3) mandibles quite slender, 3-dentate, lower process triangularly acute, covered with white pubescence, submedian in position, 4) gena wider than compound eye (9:7), with a shining, impunctate, concave area ventrally, its lower margin forming a conspicuous and rather slender process just below base of mandible, 5) vertex and gena rather dull, punctures very fine and densely crowded, face dull, densely and finely rugosopunctate beneath dense pubescence, 6) face with copious, erect, yellowish-white pubescence largely obscurring surface below level of ocelli, gena with white pubescence, rather short above, becoming dense and elongate below, vertex sparsely pubescent with erect and elongate brownish hairs, yellowish at lateral margin, 7) F1 slightly broader than long (2:1.5), longer than pedicel, and shorter than F2, which is slightly longer than broad (2.5:2), remaining flagellomeres longer than broad (3:2), apical flagellomere very slightly dilated, more elongate (4.5:2).

Mesosoma. 1) pubescence white, rather short and dense laterally and posteriorly, mesoscutum with quite copious, erect and elongate brownish hairs, becoming whitish anteriorly, scutellum with whitish pubescence, 2) punctures of mesoscutum fine and close, slightly separated only in centre, densely crowded otherwise, those of scutellum and axilla uniformly fine and slightly separated; pleura dull, punctures rather shallow but very close, becoming densely crowded above; propodeum somewhat smoother, punctures shallow, very fine and close, triangle rather dull, impunctate, 3) front coxal spine very slender and elongate, anterior surface of coxa bare and somewhat shining, with a patch of 4 or 5 elongate, reddish bristles just before base of spine; mid tibial spur well developed; front tarsus bright yellow, basitarsus enormously expanded anteriorly and apically, very deeply excavated, inner basal margin of excavation with a short fringe of brown hairs not extending beyond its basal third, the hairs otherwise entirely pale yellowish, the basitarsal scale extending fully to tip of tarsomere 2, the more posterior part of tarsomere 2 much shorter than that of 1 and 3, posterior fringe pale yellow, quite dense and elongate, more or less brownish beneath; outer surface of front tibia and posterior surface of front femur black, other surfaces more or less yellowish-brown; mid and hind basitarsi slender and simple, largely dark, the more apical tarsomeres becoming more yellowish-brown, spurs yellow, 4) tegula yellowish-brown, shining, impunctate except in anterior half, 5) wings subhyaline, veins brownish.Metasoma. 1) T2-T5 rather shallowly depressed across base, their basal margin distinct and carinate, T4 with a dense basal fascia of appressed yellow hairs arising from below the carinate lip (this often hidden under apical margin of T3); apical margin narrowly depressed on the more basal segments, becoming quite broad, more or less yellowish-hyaline and narrowly white fasciate, fasciae quite dense and conspicuous on T4 and T5; T1, and T2 basomedially with copious, elongate, pale pubescence, but T2 also with some shorter, more apical, brownish pubescence, discal pubescence of T3 and T4 short, erect, quite copious and entirely black, that on T5 largely black, but more erect and elongate; punctures of terga very fine and close throughout; dorsal surface of T6 vertical, very densely and finely rugosopunctate, carina rather short but distinct, with small, more or less rounded, median emargination, median teeth of apical margin very low, carinate, much closer to lateral angles than to each other, but these lateral angles not at all spinose; T7 rather robust, obscurely angulate medially, but not produced, 2) S1-S4 exposed, rather dull but very minutely and regularly punctate, punctures quite close but not crowded, apical margin depressed and yellowish-hyaline, that of S4 very slightly incurved across median area, apical margins with long pale hairs, though hardly forming fasciae, discal pubescence sparse and pale, not obscuring surface.

Genitalia. Plate 2.

Discussion. This common species is one of the most distinct and easily recognizable Megachile in Canada. It accepts trap nests (Medler 1964; Sheffield et al. 2008). Tepedino and Frohlich (1982) and Frohlich and Parker (1983) detail much of its biology. It is a floral specialist on Helianthus and has shown much promise as a manageable pollinator of sunflower (Tepedino and Frohlich 1982; Parker and Frohlich 1983). Divergence levels in CO1 (2.66%) suggest that the southwestern form of this species (M. pugnata pomonae) may be a distinct species, though further study is required.

Distribution: This is the most widespread member of the subgenus Sayapis; it occurs in southern Canada from NS-BC, extending north to southern NT and YT


Identification
Megachile pugnata is exceptionally distinctive in the female. The clypeus is shortened and thickened producing a vertical face in addition to the normal top face. There are two prominent submedial projections and one, broad, flattened median projection. The mandibles are longer than the eye. The mandible is widest distally and there is a prominent process on the lower margin of the inner cheek.

Names
Scientific source:

Supported by

Hosts · map
FamilyScientific name @ source (records)
Apocynaceae  Apocynum androsaemifolium @ CUIC_ENT (1)

Asclepias @ CUIC_ENT (1); AMNH_BEE (1)
Asteraceae  Achillea millefolium @ BBSL (1)

Arctium minus @ AMNH_BEE (1)

Aster rubrotinctus @ BBSL (1)

Chaenactis douglasii @ BBSL (1)

Chaenactis sp @ BBSL (1)

Cirsium arvense @ CUIC_ENT (7)

Cirsium sp @ BBSL (5)

Cirsium undulatum @ BBSL (3); AMNH_BEE (1)

Cirsium vulgare @ AMNH_BEE (15); CUIC_ENT (5)

Cirsium @ AMNH_BEE (1)

Coreopsis @ AMNH_BEE (2)

Echinacea pallida @ AMNH_BEE (4)

Echinacea @ AMNH_BEE (2)

Ericameria parryi @ BBSL (1)

Erigeron speciosus @ DART_ENT (1); BBSL (1)

Erigeron strigosus @ CUIC_ENT (1)

Grindelia sp @ BBSL (1)

Grindelia squarrosa @ BBSL (1)

Helianthus sp @ BBSL (6)

Helianthus tuberosus @ AMNH_BEE (1)

Helianthus @ CUIC_ENT (1)

Heliomeris multiflora @ DART_ENT (1)

Heliopsis helianthoides @ BBSL__ERR (1)

Heterotheca villosa @ DART_ENT (1)

Inula helenium @ CUIC_ENT (1)

Liatris spicata @ AMNH_BEE (1)

Rudbeckia hirta @ CUIC_ENT (1); AMNH_BEE (1)

Rudbeckia @ AMNH_BEE (4)

Senecio triangularis @ BBSL (1)

Taraxacum officinale @ BBSL (2)

Wyethia amplexicaulis @ BBSL (1)
Capparaceae  Cleome serrulata @ BBSL (2)
Caprifoliaceae  Symphoricarpos @ CUIC_ENT (2)
Fabaceae  Melilotus @ AMNH_BEE (1)
Hydrophyllaceae  Phacelia sp @ BBSL (2)
Lamiaceae  Salvia farinacea @ CUIC_ENT (1)
_  Fabaceae sp @ BBSL (1)

Withheld @ BBSL__YOSE (48); BBSL (41); BBSL__ZION (4)

caneberry @ NLA (1)

cucurbit @ NLA (6)

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Updated: 2017-12-11 12:46:42 gmt
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