FORAGING DYNAMICS OF PEPONAPIS PRUINOSA (HYMENOPTERA: ANTHOPHORIDAE) ON PUMPKIN (CUCURBITA PEPO) IN SOUTHERN ONTARIO

Abstract

AbstractA large population of Peponapis pruinosa, a solitary, oligolectic, ground-nesting bee and important pollinator of cucurbits in the United States and Mexico, was studied foraging on pumpkin (Cucurbita pepo) at a site in Cambridge, Ontario, from 23 July to 30 August 1990. We measured the diurnal and seasonal foraging trends for P. pruinosa and compared our findings with those for P. pruinosa elsewhere. The females are active on flowers in the mornings from dawn on. The males are active later in the mornings and spend afternoons and nights in closed flowers. The seasonal emergence of the bees closely parallels that of the plants’ anthesis. Diurnal activity is related to the availability of pollen resources on the flowers of C. pepo. Almost all pollen is removed from the synandria within 2 h of the start of foraging by female bees. Ambient temperature threshold for foraging by both sexes is about 10 °C.