The mature oocytes and ovarioles of the cleptoparasitic bees Epeoloides coecutiens (Fabricius) (Apinae: Osirini) and Ammobatoides abdominalis (Eversmann) (Nomadinae: Ammobatoidini) are described and compared, as is their chorionic microstructure. Number of ovarioles per ovary, oocyte to body-size ratios, and differences in oocyte shape and chorion structure support the conclusion that these two taxa represent different cleptoparasitic lineages.

Male and female flight behavior of Ammobatoides abdominalis is also presented as well as information on egg deposition in the cell of its host Melitturga clavicornis (Latreille) (Andrenidae: Panurginae). The strong sexual dimorphism of this cleptoparasite is noted.