A new leafcutter bee species of the genus Megachile Latreille with dark black female (Hymenoptera: Apoidea: Megachilidae) from Anguilla Bank, Lesser Antilles

A new species of Megachile Latreille, subgenus Pseudocentron Mitchell (Hymenoptera: Apoidea: Megachilidae) is described, exhibiting marked sexual dimorphism: Megachile karlquesteli new species. Only about five species of Megachile whose females have a dark black integument and predominantly black pubescence occur in the Antilles. A distinctive combination of morphological characters separates this species from other taxa. Female is characterized by a dark black tegument and pubescence, while the male possesses a dark brown tegument, darker on the metasoma, except for the tarsi and most of the foreleg, which are reddish-brown; yellow pubescence covers the frons, mesosoma, T1, and T2. The most pronounced differences, however, occur in the males, in which the structure of the apical sterna, particularly sterna 5, 6, and 8, provides reliable diagnostic features. The new species inhabits the Anguilla Bank in the Caribbean Sea. The bee was observed visiting a variety of flowers: Acanthaceae: Asystasia gangetica (L.) T. Anderson; Asteraceae: Borrichia arborescens (L.) DC., Tridax procumbens L.; Aizoaceae: Trianthema portulacastrum L.; Euphorbiaceae: Euphorbia milii Des Moul.; Goodeniaceae: Scaevola plumieri (L.) Vahl; Malvaceae: Waltheria indica L., Corchorus hirsutus L., Melochia tomentosa L.; Polygonaceae: Antigonon leptopus Hook. & Arn.; Zygophyllaceae: Guaiacum officinale L.