Genus Triepeolus Robertson, 1901

Diagnosis for Triepeolus in South America

Species of Triepeolus are non-metallic epeoliform bees that closely resemble various other cleptoparasitic bees, especially the related genera Doeringiella, Epeolus, Pseudepeolus, Rhinepeolus, and Rhogepeolus. Although no single anatomical feature is diagnostic for Triepeolus, several features in combination separate the genus from all others in South America as follows. The front coxae are quadrate (as opposed to somewhat triangular), with the trochanters widely separated at their bases, and the axillae are produced to lobes or spines and thus do not continue the contour of the mesoscutellum (as in all Epeolini); the mandibles are simple; the scapes are normal (i.e., not flattened, dramatically swollen, or each forming a laterally directed subbasal angle); the eyes are convergent below; the mesoscutum (except sometimes in T. nemoralis) and T1–T 4 in all South American (and most other) species of Triepeolus have well-defined bands of pale (white/off-white to yellow) tomentum; the mesoscutellum does not have a median longitudinal strip of pale, short, appressed setae and is to some degree bigibbous but not denticulate or tuberculate; and the fore wings of all South American (and most other) species of Triepeolus each have three submarginal cells. In the species of Triepeolus occurring in South America (as in some but not all congeners elsewhere), the pseudopygidial area of the female is known to be either triangular (with the apical margin of T5 concave) or distinctly circular (with the apical margin of T5 broadly convex).

Distribution in South America

Triepeolus is found throughout most of South America but is notably absent from much of Chile and not known to occur in southern Patagonia. The genus is expected to occur in all 12 of the continent’s countries as well as French Guiana but has not yet been confirmed from the latter, Suriname, or Uruguay (see Fig. 1).

Included species

Triepeolus alvarengai Moure, 1955

Triepeolus atoconganus Moure, 1955

Triepeolus buchwaldi (Friese, 1908)

Triepeolus cecilyae Packer, 2016

Triepeolus flavipennis (Friese, 1916)

Triepeolus nemoralis (Holmberg, 1886)

Triepeolus osiriformis (Schrottky, 1910)

Triepeolus rufotegularis (Ashmead, 1900)

Triepeolus tuberculifer Onuferko, Rightmyer & Roig-Alsina sp. nov.