Reprinted with permission from the University of Nebraska State Museum from:
Ribble, D. W. 1968. Revisions of two subgenera of Andrena, Micrandrena Ashmead and Derandrena new subgenus (Hymenoptera: Apoidea). Bulletin of the University of Nebraska State Museum 8: 1-124.
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Andrena salictaria, nigrae and illinoiensis have been much confused in collections. Nearly as many specimens of salictaria bear illinoiensis labels as they do salictaria labels and many specimens of nigrae have salictaria determination labels. The remarks on confusion in the literature under illinoiensis pertain equally well here. The male description under this species in Mitchell (1960) fits nigrae in a very important character, penis valve tip. Since illinoiensis and nigrae do not occur in Maine, the Lovell paper above probably refers to this species.
Andrena salictaria and nigrae are very closely related. The males of salictaria differ from nigrae in that they have an expanded penis valve tip. This tip is usually visible when the genital capsule is in place in the bee. Like nigrae, salictaria lacks the tuft of hairs on sternum six found in illinoiensis. The female salictaria have rather weak apical abdominal fasciae on terga 2-4. The band on tergum three is interrupted medially. Both sexes have a very large pterostigma and dark legs.
The descriptions below are based mainly on a male from Lincoln/Nebraska, May 2, 1901, M. Gary, on willow and a female from Atkinson (2 mi. W.), Nebraska, May 9, 1964, W. E. LaBerge and O. W. Isakson, on Salix. These specimens are typical of salictaria and were collected near the center of the range of the species. A total of 1,028 bees of this species were examined.
FEMALE. MEASUREMENTS AND RATIOS. — Length, 8.2 mm; width of mesothorax, 2.2 mm; wing length from tegula, 6.1 mm; facial length/width, 1.02; foveal length/width, 3.40.
INTEGUMENTAL COLOR. — Color as in illinoiensis except: head and thorax with as many deep purple as deep blue-black metallic reflections; flagellum all brown; legs all brown.
STRUCTURE. — Head as in illinoiensis except: maxillary palpus with segments in ratio of about 1.3:1.6:1.0:1.2:1.0:1.4; labial palpus with segments in ratio of about 1.7:1.0:1.0:1.3; labral process margin more even (but see below); clypeus protruding beyond lower margin of eye by almost width of eye in lateral view; clypeus much more heavily shagreened and therefore less shiny, except apex as in illinoiensis; genal area in lateral view nearly as wide as eye.
Mesosoma as in illinoiensis except: scutellar surface sculptured like mesoscutum; posterior hind tibial spur distinctly longer than anterior spur; pterostigma very large, nearly twice as wide as prestigma; first transverse cubital vein ending one and one-half vein widths from pterostigma.
Metasoma as in illinoiensis.
VESTITURE. — Hairs as in illinoiensis except: facial fovea distinctly chocolate brown; hairs of anterior mesoscutum with fewer branches; apical abdominal fasciae interrupted medially on terga 2 and 3, hairs only about one-sixth as long as exposed tergal length.
MALE. MEASUREMENTS AND RATIOS. — Length, 6.6 mm; width of mesothorax, 2.0 mm; wing length from tegula, 5.9 mm; facial length/width, 1.02; flagellar segment 1/segment 2, 1.52.
INTEGUMENTAL COLOR. — Color as in illinoiensis except: flagellum red-brown below; legs all brown.
STRUCTURE. — Head as in illinoiensis except: maxillary palpus with segments in ratio of about 1.3:1.3:1.2:1.3:1.0:1.7; labial palpus with segments in ratio of about 2.0:1.2:1.0:1.4; clypeus without shagreening in center.
Mesosoma as in illinoiensis except: sculpturing inside enclosure of propodeum coarser and less regular than surrounding areas of propodeum.
Exposed metasoma as in illinoiensis except: tergum 7 broadly rounded with posterior margin bent slightly upward; sternum 6 with broad apical emargination extending nearly to lateral margin, lateroapical corners gradually and distinctly bent downward.
Sternum 7 emarginate at apex with two large rounded lobes, each bearing numerous long branched setae (fig. 67). Sternum 8 convex, with base expanded into large plate; apex not expanded; shaft curved downward, shaft as long as base; shaft with long plumose setae reaching beyond apex, except shaft bare midbasally (fig. 68). Gonocoxite bent downward, bent part narrowed toward apex, apex slightly expanded in dorsal view, posterior half of dorsum with branched setae, dorsal lobes rounded, not projecting posteriorly. Penis valve bent downward, apex expanded into large lobe; apex reaching beyond tip of gonocoxite, protruding past sternum 8, visible when in normal position in bee; penis valve widest in middle, large lobes at base absent (figs. 64-66).
VESTITURE. — Hairs as in illinoiensis except: apical abdominal fasciae weaker; tuft of hairs on sternum 6 much less conspicuous.
VARIATION. — This species is less variable than either nigrae or illinoiensis. However, there is variation in the shape of the labral process; in the female it may be evenly rounded from side to side, squared or emarginate apically; in the male it may be squared or emarginate apically. Specimens with yellowish body hairs are commonly found. The male antennae may be all brown and the anterior margin of sternum eight is variable, emarginate or with a medial lobe.
Reprinted with permission from: Mitchell, T.B. 1960. Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin No. 141.
FEMALE — Length 7 mm.; clypeus broadly convex, projecting about one-third below suborbital line, smooth and somewhat shining, punctures exceedingly minute, well separated medially, becoming close and obscure laterally; facial foveae narrow, occupying above about half of space between eyes and ocelli, covered with pale ochraceous tomentum; space between margin of vertex and lateral ocelli much narrower than their diameter; cheeks slightly narrower than eyes, rounded posteriorly, somewhat shining beneath the rather dense pubescence; malar space lacking; basal segment of flagellum subequal to 2nd and 3rd combined; process of labrum quite small, semicircular, about twice as broad as long; pubescence of head, thorax and legs pale ochraceous to whitish; thoracic integument dull, finely tessellate, somewhat purplish, punctures of scutum extremely minute and obscure, well separated, becoming sparse posteriorly, fine and rather close on the more shining scutellum; pleura without visible punctures; dorsal area of propodeum nearly horizontal, rather extensive, triangle tessellate, not contrasting with adjacent areas; propodeal corbicula rather short, without a well defined anterior fringe, whitish; trochanteral floccus white, quite well developed, but rather short; hind tibiae somewhat broadened apically, apex nearly twice width of basitarsi, scopa quite dense, hairs rather short, simple, entirely white; all tarsi pale ferruginous, front and middle basitarsi slightly narrower than their respective tibiae; 2nd submarginal cell considerably shorter than 3rd, receiving 1st recurrent near middle; abdominal terga smooth but rather dull, the more basal segments microscopically tessellate, punctures inevident, surface obscurely purplish, apical depressed areas narrow and shallow, yellowish-hyaline, discal pubescence extremely short and sparse, entirely pale, terga 2-4 with narrow, white, apical fasciae, interrupted on tergum 2 and more narrowly on 3, tergum 5 with a pale brownish, apical fimbria.
MALE — Length 7 mm.; clypeus only very slightly convex, projecting very slightly below suborbital line, very closely and finely punctate beneath short, dense pubescence; space between margin of vertex and lateral ocelli much narrower than their diameter; cheeks slightly narrower than eyes, rounded posteriorly, densely pubescent; malar space lacking; basal segment of flagellum slightly shorter than 2nd and 3rd combined, 2nd much broader than long, segments beyond 2nd pale ferruginous beneath; process of labrum semicircular, fully twice as broad as long; mandibles short, with a small but distinct inner subapical tooth, overlapping hardly at all; pubescence of head, thorax and legs entirely pale ochraceous, rather short but rather dense; thoracic integument dull, finely tessellate, punctures of scutum very minute and obscure, well separated, becoming rather sparse posteriorly, exceedingly minute and quite sparse on scutellum, surface obscurely purplish; pleura not visibly punctate; dorsal area of propodeum quite extensive, nearly horizontal, triangle finely roughened; all basitarsi slender and elongate, considerably narrower than their respective tibiae, pale ferruginous; 2nd submarginal cell much shorter than 3rd, receiving 1st recurrent slightly beyond middle; abdominal terga smooth but rather dull, microscopically tessellate, obscurely purplish or greenish, not visibly punctate, apical depressed areas rather narrow and shallow, becoming yellowish-hyaline along rims, discal pubescence extremely short and sparse, entirely pale, the fasciae very poorly developed; apical portion of sternum 8 very narrow and slender, tip narrowly rounded, covered beneath with rather long, dense pubescence; penis valves bulbous medially, slightly narrowed toward base and produced apically into a sharp, slender, spine-like tip, gonocoxites slender, rather abruptly flexed medially, strongly narrowed apically, gonocoxal lobes not at all produced.
DISTRIBUTION — Colorado to the New England states and Nova Scotia, south to North Carolina, Georgia and Mississippi; March to May.
FLOWER RECORDS — Crataegus, Prunus, Pyracantha and Salix. Robertson (1929) records salictaria also on Amelanchier, Antennaria, Erigenia, Rhus, Sassafras and Viburnum.