A recent study by the University of Illinois shows that honeybees may actually prefer sugar sources with laced with some common pesticides. This research highlights the unique ways agricultural practices can affect a variety of organisms in unique and unexpected ways, as well as honeybees’ distinct evolutionary history. The results are also startling because Honeybees populations have been decreasing, and there have been many studies showing the detrimental effects of various pesticides to honeybee populations. These honeybees may actually be killing themselves, or hurting themselves in other ways.

The researchers performed their study by setting up two feeder stations and used syrups, with pesticides or without. Honey bees could fly between the two stations freely and choose which sugar source they preferred. In the study, they tested nine naturally occuring chemicals, three common fungicides and two common herbicides. They also used different concentrations of all their chemicals tested.

While the bees avoided the syrups with high pesticide concentrations, in lower concentrations, the honeybees actually preferred the pesticide lace sugar sources. The widely used herbicide, Glyphosate, was one of the chemicals that honeybees seemed to show a preference for.

Another preferred pesticide in this study was Chlorothalonil, a commonly used fungicide in the United States. However in other studies, this fungicide has been linked to contraction in range of different honeybees. Another recent study found a positive correlation between Chlorothalonil use and presence of the fungal parasite Nosema bombi  in declining bee populations. Another recent study showed that fungicides may disrupt the bees’ ability to metabolize certain acaricides which are used to control varroa mites, which can infest honeybee hives.

The results in this study are troubling for honeybee colonies and somewhat perplexing. Further studies will hope to shed more light on honeybees preferences for different food sources as well as provide options for farmers and pest control advisers that will protect bee populations, while controlling other pests.

Sources:

Acaricide, Fungicide and Drug Interactions in Honey Bees (Apis mellifera). Johnson et al. PLOS Biology. 2013.

Landscape predictors of pathogen prevalence and range contractions in US bumblebees. McArt et al. The Royal Society Publishing. 2017