Honey Bee Exposure to Pesticides: A Four-Year Nationwide Study

Abstract

Pollinators, including honey bees, are responsible for the successful reproduction of more than 87% of flowering plant species: they are thus vital to ecosystem health and agricultural services world-wide. To investigate honey bee exposure to pesticides, 168 pollen samples and 142 wax comb samples were collected from colonies within six stationary apiaries in six U.S. states. These samples were analyzed for evidence of pesticides. Samples were taken bi-weekly when each colony was active. Each apiary included thirty colonies, of which five randomly chosen colonies in each apiary were sampled for pollen. The pollen samples were separately pooled by apiary. There were a total of 714 detections in the collected pollen and 1008 detections in collected wax. A total of 91 different compounds were detected: of these, 79 different pesticides and metabolites were observed in the pollen and 56 were observed in the wax. In all years, insecticides were detected more frequently than were fungicides or herbicides: one third of the detected pesticides were found only in pollen. The mean (standard deviation (SD)) number of detections per pooled pollen sample varied by location from 1.1 (1.1) to 8.7 (2.1). Ten different modes of action were found across all four years and nine additional modes of action occurred in only one year. If synergy in toxicological response is a function of simultaneous occurrence of multiple distinct modes of action, then a high frequency of potential synergies was found in pollen and wax-comb samples. Because only pooled pollen samples were obtained from each apiary, and these from only five colonies per apiary per year, more data are needed to adequately evaluate the differences in pesticide exposure risk to honey bees among colonies in the same apiary and by year and location.

Landscape factors influencing honey bee colony behavior in Southern California commercial apiaries

“…Beebread may be the most revealing matrix for estimating the concentrations and diversity of agrochemicals bees are exposed to at a given point in time 6 . A recent study found that among 6 geographically disparate apiaries in the US, 79 different pesticides and metabolites were observed, with up to 10 distinct modes of action 27 . While wax and honey can last for many months or even years, bees prefer pollen <72 h old 28 , so it would more likely reflect the hive's recent environment than wax or honey.…”

Distribution of coumaphos in beeswax after treatment of honeybee colonies with CheckMite® against the parasitical mite Varroa destructor

“…As a result, residues from coumaphos-containing drugs have been found in the beeswax of European origin, as reported for Belgium (Ravoet et al 2015), France (Chauzat et al 2011), Germany (Wallner 1999), Switzerland (Bogdanov 2006), Italy (Boi et al 2016;Porrini et al 2016;Perugini et al 2018) and Spain (Orantes-Bermejo et al 2010;Calatayud-Vernich et al 2017;Lozano et al 2019), and also reviewed recently in Wilmart et al (2016). Substantial coumaphos levels have also been found in the beeswax of apiaries outside of Europe, such as for example in North America (Mullin et al 2010;Wu et al 2011;Ostiguy et al 2019;Fulton et al 2019) or Uruguay (Harriet et al 2017). A common beekeeping practice is to recycle old wax combs to produce new wax foundation sheets on which bees build their combs.…”

Factors affecting the reproductive health of honey bee (Apis mellifera) drones—a review

“…The widespread use of pesticides in a variety of crop systems has contributed to an ongoing risk of pesticide exposure for honey bees (Johnson et al 2010;Ostiguy et al 2019). Several studies have described adverse effects of worker exposure to various neonicotinoids including imidacloprid, clothianidin, and thiamethoxam (Aliouane et al 2009;Schneider et al 2012;Di Prisco et al 2013).…”