The discovery of an eclosed egg of the Old World Dioxys cincta (Jurine) attached to the brood cell wall of Osmia (Osmia) cerinthidis Morawitz indicates that the female of the cleptoparasite deposited her egg before the host female closed the cell. This contrasts with previously published information concerning the North American Dioxys pomonae Cockerell, which deposited her eggs in the cells of Osmia (Acanthosmioides) nigrobarbata Cockerell after the host female had oviposited and closed the cell (J.G. Rozen, Jr., and M.S. Favreau. 1967. Journal of the New York Entomological Society 75:197–203). Such a change in the mode of cleptoparasitism within a single evolutionary lineage is an uncommon phenomenon among cleptoparasitic bees and invites biogeographic speculation on the oviposition habits of other Dioxyini.

The brood cells of Osmia cerinthidis were constructed in the vacated brood cells of Anthophora (Anthophora) fulvitarsis Brullé and A. (Melea) plagiata (Illiger).