Reprinted from Rightmyer 2008. A review of the cleptoparasitic bee genus Triepeolus (Hymenoptera: Apidae).—Part I. Zootaxa 1710.
Description.—Length ca. 11.5–15 mm; ITW 2.4–3.0 mm. Integument black, with red medially on mandible
and outer F1; dorsum of mesosoma and metasoma with bands of pale yellow setae. Clypeus lacking or with
faint dorsal midline, with faint larger punctures on field of very fine and dense punctures. Paramedian band
reaching anterior margin of mesoscutum, separated from or nearly contiguous laterally with pale setae on
anterior margin of mesoscutum. Scutellum strongly bigibbous; axillar spine triangular, reaching midpoint of
scutellum, apical point slightly incurved. Mesepisternum lacking erect, simple setae; with small patch of pale
yellow, branched setae posterior to pronotal lobe, otherwise mostly asetose; with very fine, nearly contiguous
punctures, grading ventrally to slightly larger, more widely-spaced punctures (punctures separated by up to
almost one puncture diameter in some places). T1 discal patch ovate to quadrate; T2 with LLB reduced or
forming obtuse acute angle with ATB. Female: Pseudopygidial area very distinctive, long and narrow with
basal patch of fine, slightly paler reflecting setae, with median, elevated, inverted U or V-shaped ridge, and
apical circular patch of coarse setae; T5 entirely black; S5 tapered anteriorly and slightly downcurved. Mesosoma
and metasoma venter entirely black/brown. Male: Pygidial plate keyhole shaped, with distinct transverse
basal ridge and apical downturned plate; ventral metasoma with black setae; S3 apical setae very
slightly surpassing apical margin; S4–S5 with true apical fringes of black setae.
Comments.—Females of this species are readily distinguished by the entirely unique pseudopygidial area
(See Fig. 213 and description, above).
Distribution.—USA: Colorado, Kansas, Utah.
Floral Records.—Helianthus salicifolius A. Dietr., Solidago sp.
Seasonal Records.—26 July to 19 October.
