First record of donacid beetle larvae of Macroplea appendiculata (Panzer, 1794) (Coleoptera: Chrysomelidae: Donaciinae) within Dreissena polymorpha (Pallas, 1771) (Bivalvia: Dreissenidae) in the Kelkolovo quarry (Leningrad Oblast, Russia)

Dreissena polymorpha is recognized as a powerful habitat engineer species in most aquatic ecosystems. An unusual association between the larvae of Macroplea appendiculata and D. polymorpha was discovered in the Kelkolovo quarry (Leningrad Oblast, Russia). Specifically, the larvae of M. appendiculata were found embedded within a small zebra mussel druse attached to the roots of aquatic plants. The possible nature of donacid beetle and zebra mussels association is discussed.