Reprinted from Rightmyer, M. 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).—Part I. Zootaxa 1710.
Description.—Length ca. 9–14.5 mm; ITW 1.8–2.5 mm. Integument black to brown, with red or orange on base of mandible, entire labrum, and legs (excluding basal coxae and spine), usually on part or all of clypeus,
entire scape, pedicel, and F1, pronotal lobe, and tegula, sometimes on mesepisternum and venter of mesosoma and metasoma; dorsum of mesosoma and metasoma with bands of pale yellow setae. Clypeus shining, lacking
or with very weak midline, with distinct large punctures and minute, weakly impressed punctures. Paramedian band clearly separated from other pale setae on mesoscutum (females and some males) or joined
laterally to pale setae on anterior margin of mesoscutum (most males); mesoscutum shining. Scutellum weakly bigibbous, slightly flattened and extended posteriorly; axillar spine triangular, not or barely reaching
scutellum midpoint. Mesepisternum lacking erect, simple setae; upper third (including hypoepimeron) covered with dense, pale yellow, branched setae (females), or with pale, branched setae also on ventral margin, sometimes medially with sparse, pale, branched setae (males); ventrally mostly asetose with relatively small,
weakly impressed punctures, separated by up to two puncture diameters. T1 discal patch widely rectangular to quadrate; T2 with LLB forming weakly acute to acute angle with ATB. Female: Pseudopygidial area similar to that of T. concavus (i.e., with long, stout setae forming posterior plate-like structure); T5 with narrow band of white setae on apical margin lateral to pseudopygidial area; S5 strongly downcurved. Male: Pygidial plate keyhole shaped, with distinct transverse basal ridge and downturned apical plate; S2–S3 with white apical
bands of setae, (S2 with white setae surpassing apical margin); S4–S5 with apical fringes entirely white, brown, or (most commonly) white laterally and brown medially.
Comments.—Although I was unable to locate the type of T. penicilliferus, the original description leaves no doubt as to the identity of this species. Triepeolus penicilliferus is extremely similar to T. subnitens, but can be separated from that species by the pseudopygidial area (very short and wide, seemingly formed by the
downturned integument in T. subnitens), and by the female S5, which is strongly downcurved in T. penicilliferus but only very slightly downcurved in T. subnitens. Although the distributions of the two species overlap, T. penicilliferus appears to be most abundant in Texas, while T. subnitens appears to be most abundant in California. Males of the two species are difficult to differentiate, but may be separated based on the following characters: the pronotal lobe tends to be red in T. penicilliferus and brown in T. subnitens; the clypeus in profile tends to be flatter in T. penicilliferus than in T. subnitens; the mesepisternum tends to be less densely punctate
and less setose in T. penicilliferus than in T. subnitens; and the pygidial plate is narrower, with a more distinct transverse basal ridge in T. penicilliferus than in T. subnitens.
Distribution.—MéXICO: Chihuahua, Coahuila, Durango, Sonora, Tamaulipas; USA: Arizona, California (Riverside Co., San Bernardino Co.), Colorado, Kansas, Missouri, New Mexico, Oklahoma, Texas.
Host Records.—Svastra (Epimelissodes) sabinensis sabinensis (Cockerell) (Rozen, 1983, adult entering nest).
Floral Records.—Bahia absinthifolia var. dealbata (Gray) Gray, Bebbia juncea (Benth.) Greene, Coreopsis sp., Eriogonum deflexum Torr., Gaillardia suavis (Gray & Engelm.) Britt. & Rusby, Gutierrezia sarothrae (Pursh) Britt. & Rusby, Helenium microcephalum DC., Heterotheca subaxillaris (Lam.) Britt. & Rusby, Kallstroemia grandiflora Torr. ex Gray, Larrea tridentata (Sessé & Moc. ex DC.) Coville, Nepeta cataria L., Opuntia sp., Psilostrophe cooperi (Gray) Greene, Ratibida columnifera (Nutt.) Woot. & Standl., Senecio douglasii [= Senecio flaccidus Less. var. douglasii (DC.) B.L. Turner & T.M. Barkl.], Silphium asperrimum (= Silphium radula Nutt.), Sphaeralcea sp., Verbena halei Small, Verbesina helianthoides Michx., Viguiera stenoloba Blake.
Seasonal Records.—12 April to 16 October.
|