Foraging Behaviour of Apis mellifera scutellata and Hypotrigona gribodoi Bees in Monoculture and Polyculture Vegetable Gardens

Abstract

This study aimed to evaluate the influence of crop type, cropping systems and weather elements on foraging behaviour of pollinators, which is imperative for designing pollinator friendly agricultural systems. Generalised linear models were used to assess foraging time and visitation frequency of the honey bee Apis mellifera scutellata and the stingless bee Hypotrigona gribodoi across monocultures and polyculture systems of butternut, dry bean and mustard at two garden sites in Zvimba district, Zimbabwe. A total of 120 bee visitations across the crops and 103.4 min of foraging bouts were recorded. The honey bee had longer foraging bouts periods in monoculture system, but there were no differences in the stingless bee. Across the two bee species, mustard had the longest foraging bouts, and least in dry beans. Foraging time generally decreased with increasing temperatures, but the decreases in polyculture systems were less severe for the honey bee. Only the honey bee foraging time was shorter in the presence of competitors. We therefore conclude that there are possible negative impacts of projected increases in temperature due to global warming and agricultural intensification on foraging behaviour of important pollinators such as bees.