Species of Megachile (Chrysosarus) with a partial cutting edge in the female mandible (Hymenoptera, Megachilidae) in Argentina, Chile and Uruguay (Hymenoptera, Megachilidae)

A. ROIG ALSINA; TORRETTA, JUAN PABLO

Revista del Museo Argentino de Ciencias Naturales

Museo Argentino de Ciencias Naturales

Año: 2023 vol. 25 p. 225 - 247

The subgenus Megachile (Chrysosarus) is known for the lack of cutting edges in the female mandible. Nevertheless, a small cutting edge on the lower margin of the third tooth is present in a few species, all described from Brazil. This contribution calls attention to the presence of this condition in several species occuring in Argentina, Chile, and Uruguay. Four new species are described: M. basimacula, M. platensis, M. sancticlaudii, and M. simpliciclypeata. The identity of two species described over a century ago is clarified: M. interjecta Vachal, and M. cubiceps Friese. Megachile uncinata González, Griswold & Engel is a junior synonym of M. cubiceps Friese. Species of M. (Chrysosarus) with a small cutting edge in the female mandible form an heterogeneous assemblage, and seem to be related to species that completely lack cutting edges, and not to each other. A probable exception is the group formed by the four species M. basimacula, M. cubiceps, M. euzona, and M. tetrazona, which share a number of common features, and are included as the M. euzona species group. Descriptions, illustrations, and distributional data are presented for all treated species