Abstract: Despite the unique lifestyle of reed beetles (Chrysomelidae, Donaciinae) and the long-time interest that this peculiar group enjoyed among biologists, many aspects of their ecology remain unknown or understudied. In this communication, I verify, by observations in the laboratory and in the natural habitat, the contradictory statements of the previous authors regarding adult feeding and oviposition in the reed beetle Plateumaris braccata. The temperature dependence of embryonic development in this species is also assessed. The lower temperature threshold for development is smaller and the sum of degree-days is greater than is typically found in the other leaf beetles studied.