Dufourea marginata (Cresson, 1878)
Dufourea marginata Female |
Dufourea marginata Male |
Panurgus marginatus Cresson, 1878: 62 (♀ description).
Panurgus halictulus Cresson, 1878: 63 (♂ description). Preoccupied.
Panurgus autumnalis Robertson, 1895: 121 (♀ description).
Dufourea (Halictoides) marginata halictella Michener, 1951: 1132.
Diagnosis.The main diagnostic characters of this species are the presence of yellowish body pubescence, the nearly bare supraclypeal area, impunctate apical triangular area on clypeus, and the dull terga. Those observed in the male: flagellar segments longer than broad and yellow-orange below, and fore and hind trochanters simple. This species is similar to D. trochantera in its small size and broad head, however the latter has the male with dark antenna and produced trochanter, and the female with a densely pubescent supraclypeal area and the absence of an impunctate area on clypeus.
FEMALE: Length 7.5-8 mm.
Head:
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Dufourea marginata female head
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1) head slightly broader than long, 1.11:1; compound eyes subparallel; OVD = 1.5MOD, OOD = 2.5MOD, IOD = 2MOD. 2) supraclypeal area mostly shiny, nearly flat in lateral view, with slightly elevated midline, carinate between antennae; clypeus short and very broad, not markedly convex nor protuberant, rather flattened; paraocular lobe slightly protuberant, shiny and impunctate; labrum much broader than long, largely occupied by the truncate labral process. 3) mandible bi-dentate. 4) genal area narrower than compound eye, much narrowed below. 5) pubescence largely yellow, longest on apical clypeal margin, mandible, lower genal area; supraclypeal area nearly bare. 6) punctures on upper part of face very fine and close, densely crowded medially (3pd). 7) IAD slightly smaller than AOD; antennal socket separated from upper margin of clypeus by slightly more than its diameter; antenna dark brown, becoming orange laterally, F1 nearly as long as broad, shorter than pedicel which is slightly elongate, remaining segments broader than long, except apical segment which is slightly longer than broad.
Mesosoma:
8) pubescence largely yellow on dorsal mesosoma, whitish-yellow on lateral mesosoma, legs, longest on fore and hind femur, hind tibia, and mesopleuron; mesoscutum with long sparse hairs among dense short hairs covering surface, mesoscutellum and metanotum with long branched hairs, longer than those on mesoscutum. 9) mesoscutum dull, densely tessellate, punctures extremely crowded, separated by
Metasoma:
13) terga shiny with minute imbrications, minutely and quite closely punctate, especially on T1 and T2 where punctures are deep and distinct (2-4pd), becoming shallow on the more apical terga (>3pd), becoming sparser and somewhat obscure on T4-T5; apical impressed areas yellowish-hyaline and impunctate; discal pubescence very short, suberect, entirely pale, becoming longer and denser laterally on apical impressed areas, more copious on T4-T5. 14) sterna dull, closely punctate (1-2pd) in apical half, with basal areas yellowish-hyaline and impunctate, widest medially, narrowing laterally.
MALE: Length 8-8.5 mm.
Head:
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Dufourea marginata male head
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1) head broader than long; compound eyes short, subparallel; OVD = 1.5MOD, OOD = 2MOD, IOD = 2.5MOD. 2) supraclypeal area dull and nearly flattened in lateral view; clypeus somewhat protuberant, very broad and short, densely pubescent; labrum shiny, much broader than long. 3) mandible bi-dentate. 4) genal area above narrower than compound eye and much narrowed below. 5) pubescence pale yellowish, quite copious, longest on lower genal area and vertexal area; supraclypeal area and clypeus densely covered in golden-white hairs, lower paraocular area with dense hairs only lowermost area; long dark hairs among pale ones on scape and vertexal area. 6) face between ocelli and antennae with very fine and densely crowded punctures (2pd). 7) IAD much smaller than AOD (1.5X), antennal socket separated from upper margin of clypeus by more than its diameter; F1 very slightly longer than broad, slightly longer than pedicel and half as long as F2, F2 about twice as long, following segments somewhat shorter, dark brown above, golden yellow beneath.
Mesosoma:
8) pubescence pale yellowish-white, quite copious; longest near basal margin of mesoscutum, mesopleuron, and mesoscutellum. 9) mesoscutum rather dull, punctures very fine, densely crowded (2pd); hypoepimeral area strongly imbricate on upper ¼, punctures dense but becoming sparse apically; propodeal triangle subequal in length to mesoscutellum, minutely imbricate, very finely and irregularly striate, lateral striations distinct and well separated, margin rounded and smooth; lateral and posterior propodeal surfaces smooth and somewhat shiny, punctures quite close, shallow and rather indefinite, separated by 1-2pd. 10) legs mostly brown, apical tarsal segments becoming yellowish hyaline; hind femur and tibia slender and simple, mid tibial spur about 1/3 as long as mid basitarsus; hind basitarsus slender, about 4 times as long as broad. 11) tegula slightly reddened, outer margin more yellowish-hyaline; anterior half imbricate with fine punctures (2-4pd), becoming sparse posteriorly where surface is shiny; with long white hairs along surface. 12) wings whitish, veins and stigma pale golden brown, recurrent veins entering 2nd submarginal cell subequally distant from base and apex.
Metasoma:
13) metasomal terga smooth but dull, minutely and closely punctate (
Genitalia: Dorsal view
Ventral view
Dufourea marginata genitalia, dorsal view
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Dufourea marginata genitalia, ventral view
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Distribution:
In Canada, this species is known from southern British Columbia to Ontario (see Map).
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Map: Canadian distribution of Dufourea marginata
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