Bumblebees, bambus spp., foraging on Red Oak, quercus rubra, acorn galls in Southern Ontario

Abstract

Bumblebees and other aculeate Hymenoptera were observed collecting a secretion associated with galls of Callirhytis operator (Cynipidae) on acoms of Red Oak (Quercus rubra) at Lake Matchedash, Ontario, in August 1996. This is the first record of bumblebees collecting gall secretions, which may be a locally important sugar source during mast years.