Bees provide vital pollination services to the majority of flowering plants in both natural and agricultural systems. Unfortunately, both native and managed bee populations are experiencing declines, threatening the persistence of these plants and crops. Agricultural chemicals are one possible culprit contributing to bee declines.
Even fungicides, generally considered safe for bees, have been shown to disrupt honey bee development and impair bumblebee behaviour. Little is known, however, how fungicides may affect bumblebee colony growth.
Researchers at the University of Winsconsin and USDA conducted a controlled cage study to determine the effects of fungicide exposure on colonies of a native bumblebee species (Bombus impatiens). Colonies of B. impatiens were exposed to flowers treated with field-relevant levels of the fungicide chlorothalonil over the course of one month.
Colony success was assessed by the number and biomass of larvae, pupae, and adult bumble bees. Bumblebee colonies exposed to fungicide produced fewer workers, lower total bee biomass, and had lighter mother queens than control colonies. Their results suggest that fungicides negatively affect the colony success of a native bumblebee species and that the use of fungicides during bloom has the potential to severely impact the success of native bumblebee populations foraging in agroecosystems.
The full research paper can be viewed and downloaded from: www.mdpi.com/2075-4450/6/2/478
Attribution: Multidisciplinary Digital Publishing Institute (MDPI), a peer-reviewed platform for scientific open-access journals operated by MDPI AG, based in Basel, Switzerland.
Posted 22 June 2015