Department of Entomology

Title: “The influence of a prominent natural enemy and seasonal variation in food resources on bumblebee (Bombus spp.) colony performance ”

Abstract: Resources and natural enemies are considered to be important drivers of the population dynamics of wild bees, yet there is little information on how these factors, independently or in combination, influence the demographic performance of wild bee species. Bumblebees (Bombus spp.), an ecologically and economically important group of social bees, have colony cycles that last many weeks prior to the production of reproductive offspring. Although sustained forage availability throughout the colony cycle is deemed important for reproduction, few studies have evaluated how natural, temporal variation in flower availability influences bumblebee colony performance. Likewise, the effects of natural enemies on colony success are largely unknown. Malfi will discuss her use of radio frequency identification (RFID) technology and an individual-based simulation model in evaluating how two seasonally variable factors, floral resource abundance and parasitism by endoparasitic conopid flies (Conopidae, Diptera), together affect bumblebee (Bombus impatiens) colony productivity. She will also discuss her current efforts to understand how short food resource pulses affect the demography (i.e. growth, reproduction) of a western bumblebee (B. vosnesenskii) through manipulations of resource levels in field colonies and the detailed tracking of marked workers within those hives.