Reprinted with permission from: Rightmyer, M.G. A Review of the Cleptoparasitic Bee Genus Triepeolus (Hymenoptera: Apidae)
TRIEPEOLUS NEVADENSIS (CRESSON)
Epeolus nevadensis Cresson 1878: 86 [Lectotype: Academy of Natural Sciences No. 2220; female, Nevada]; Cresson 1916: 125 [lectotype designation].
Triepeolus nevadensis; Robertson 1901: 231.
Description.—Length ca. 12.5–14 mm; ITW 2.6–2.9 mm. Integument black, with red on basal half of mandible; sometimes with orange labrum and F1; dorsum of mesosoma and metasoma with bands of yellow setae. Clypeus shining, mostly asetose, lacking midline, with large punctures. Preoccipital carinae on gena and posterior margin of head behind vertex. Mesoscutum and scutellum shining; mesoscutum with dense band of setae on anterior fourth, with paramedian band barely distinct from dense anterior setae. Scutellum flattened and somewhat extended posteriorly; axillar spine not attaining midpoint of scutellum, rounded apically. Mesepisternum lacking erect, simple setae; with distinct area of yellow, branched setae on dorsal half to third (including hypoepimeron); ventrally with brown, branched setae; punctures small and contiguous. T1 discal patch distinctly rectangular. T2 with LLB forming conspicuous right angle with ATB. Mesosoma and metasoma venter entirely dark brown (except males with white apical band of setae on S3). Female: Pseudopygidial area uniformly dark, “glossy”; poorly differentiated from rest of T5 (T5 usually lacking pale setae, but sometimes with pale setae lateral to pseudopygidial area), S5 not downcurved. Male: Pygidial plate of moderate size, keyhole shaped, with strong basal transverse ridge, forming downturned apical plate; S3 with white apical band of setae (sometimes brown medioapically), setae medially weakly surpassing apical margin; S4–S5 with brown apical fringes.
Comments.—Triepeolus nevadensis is superficially similar to T. concavus, but can be separated by the following characters of T. nevadensis: the clypeus is shining with distinct larger punctures, the mesoscutum is shining, the paramedian bands are isolated from the yellow setae on the anterior margin of the mesoscutum (though weakly developed), the scutellum is flattened and somewhat extended posteriorly, the T1 discal patch is strongly rectangular, and the T2 LLB forms a 90 degree angle with the ATB. The female pseudopygidial area of T. nevadensis is completely different from that of T. concavus, appearing poorly differentiated from the rest of T5, darkly shining, flat, and quadrangular; also, S5 is not downcurved. Triepeolus nevadensis is also similar to T. remigatus, but in T. nevadensis the paramedian bands are not so strongly developed as in T. remigatus, the mesoscutum is more distinctly shining, the scutellum is more flattened and extended posteriorly, and the T1 discal patch is distinctly rectangular (as opposed to ovate or subtriangular in T. remigatus). The males have white banding only on S3 (as opposed to both S2 and S3). The female pseudopygidial areas are similar, but the species can be differentiated by the other characters listed above. Triepeolus nevadensis is also similar to T. robustus in overall appearance, but can be distinguished from that species by the lack of dense, erect setae on the upper face, which, in T. robustus, causes the clypeus to appear to be recessed.
Distribution.—MÉXICO: Chihuahua, Durango; USA: Georgia, Nevada, New Mexico, North Carolina, Oklahoma, Texas.
Floral Records.—Monarda citriodora Cerv. ex Lag., M. punctata L., Vernonia glauca (L.) Willd.
Seasonal Records.—3 May to 27 September.
Specimens examined.—21 female, 2 male (BOULDER, DAVIS, LAWRENCE, NEW YORK, PHILADELPHIA, RALEIGH, SAN FRANCISCO, WASHINGTON D.C.).
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 13-15 mm.; entirely black, including legs, tubercles, tegulae and labrum, the mandibles slightly reddened; basal segment of flagellum somewhat reddened, median segments somewhat longer than broad; space separating lateral ocelli from margin of vertex slightly less than their diameter; cheeks very narrow, less than half width of eyes, still narrower below, posterior margin carinate; median length of labrum about two- thirds the breadth, with a pair of minute and obscure apical denticles; posterior margin of scutellum broadly outcurved, very slightly depressed medially, free part of axillae hardly evident, joined for nearly entire length to sides of scutellum, tips not reaching mid transverse line (fig. 112) ; wings subhyaline basally, becoming lightly infuscated apically, with the usual three submarginal cells, veins brownish to piceous; face with no appressed pale tomentum but with some suberect, rather copious black pubescence just above antennae, which is in part yellowish; margin of pronotum, entire tubercles, adjacent upper part of pleura, and narrow margin encircling central disc of scutum, yellow tomentose; metanotum and adjacent margin of scutellum densely pale yellow tomentose, with tufts of elongate yellowish pubescence at each extreme side just back of wing bases; posterior face of propodeum with a pale tomentose area on each side above; pleura below densely black tomentose, partially obscuring the surface; basal abdominal tergum with a rather narrow, quadrangular, black tomentose patch which is bordered on each side and apically with dense yellow tomentum, apical band rather narrow, somewhat removed from rim of tergum, lateral areas very broad, the basal tomentum widely interrupted medially; tergum 2 with a transverse, subapical, yellow tomentose band which is abruptly broadened on each extreme side, nearly attaining basal margin; terga 3 and 4 with transverse, tomentose bands, that on 3 somewhat removed from margin, that on 4 somewhat less so, 5 with rather restricted, oblique, pale tomentose areas on each side of pseudopygidium; face between antennae and ocelli with deep, distinct, rather sparse punctures in part, these becoming close toward antennae, very fine and close across vertex and on cheeks; face below antennae shining, only microscopically punctate, but with scattered, rather coarse and deep punctures over clypeus and supraclypeal area; scutum shining beneath blackish tomentum, punctures minute and slightly but not widely separated; scutellum very closely and finely punctate, surface densely black tomentose, and axillae minutely and closely punctate; pleura very finely and densely punctate throughout; punctures of abdominal terga minute and densely crowded throughout, largely obscured by black tomentum; pseudopygidium rather broadly rounded apically, basal margin indefinite, median length only slightly more than half the breadth, surface somewhat shining, covered with suberect, fine, blackish bristles; sternum 5 broadly convex as seen from beneath.
MALE—Answers in general to description of female, but with a small patch of conspicuous yellowish tomentum on each side of face between antennae and eyes; scutellum more deeply grooved medially; tergum 5 with an apical, transverse, tomentose fascia, but tergum 6 completely black; sternum 3 with a quite conspicuous, transverse, white fascia which is slightly interrupted medially, sterna 4 and 5 with subapical fringes of elongate, apically flexed, black setae; pygidial plate strongly elevated above disc of tergum 7, median length beyond transverse ridge somewhat greater than breadth at that point, margin carinate, rather narrowly rounded, surface with a few shallow and obscure pits, the more basal area minutely punctate and with subappressed tomentum.
DISTRIBUTION—Nebraska and Texas to North Carolina and Georgia; June to September. Flower records by Robertson suggest the probability that he collected nevadensis in Illinois.
FLOWER RECORDS — Vernonia. Robertson’s (1929) list includes Cirsium, Helianthus, Monarda, Pycnanthemum and Verbena.