Winter occurrence of diprionid larvae (Hymenoptera, Symphyta) on pines in Central Europe: an effect of global warming?

Abstract

During two winter seasons (2013–2014 and 2014–2015), we collected insects from branches of Scotch pine trees in the Borská nížina lowland (western Slovakia) using beating method. Four hymenopteran species in the larval stage were recorded in December 2013: Diprion similis (Hartig, 1834), Gilpinia frutetorum (Fabricius, 1793), Gilpinia pallida (Klug, 1812) and Gilpinia variegata (Hartig, 1834). The occurrence of diprionid larvae in the non-growing season has not been so far reported from Central Europe and may be a result of global warming.