Bumblebees

Sandra Gillespie, a PhD student in OEB, studies the impacts of parasties of native pollinators on plant reproduciton. While much attention has been payed to recent declines in honeybee populations, few people are aware that many of our native pollinators are also in decline. Bumblebees (Bombus spp.) are abundant native pollinators in North America, and are important for reproduction of many native plants as well as crop species. However, only a handful of scientists study bumblebee parasites and next to nothing is known about how these parasites might impact the pollinator service that these insects provide to plants. Sandra conducts surveys of of several type of parasites at many sites in western Massachusetts in order to understand how the abundance of these parasites relates to reproduction of native plants. These parasites include a parasitoid fly that lays its eggs in adult bumblebees. The larvae develop inside the bee, feed on its guts, and eventually kill it. Evidence suggests that parasites such as these not only eventually kill the bee, but also affect its behavior, such that is may be a less effective pollinator duing its lifetime.