This note reports for the first time a "male sleeping aggregation" of the solitary bee Oxaea austera Gerstaecker, 1867 (Hymenoptera, Apoidea, Oxaeinae) found near the town of Iaçú, Bahia, in Northeastern Brazil. This is also the first record of a species of Oxaea for the caatinga ecosystem.
Oxaea austera; solitary bee; male sleeping aggregation; caatinga; Brazil