Abstract
Pollen might be contaminated by multiple pesticides representing a risk for long-term contamination of honeybees when collected. Standardized methodology to assess the effects of pesticide mixtures under field conditions is lacking. We conducted an experiment on chronic feeding of a diet contaminated with a field-realistic pesticide mixture on free-flying honeybee colonies. Pesticide residues in larvae and adult tagmata were detected in trace amounts. In colonies treated with a pesticide mixture, larval weight was higher and acini diameters of the hypopharyngeal glands of nurse bees were smaller than in the untreated control. Brood termination and adult lifespan did not differ between both groups. Our study offers a reproducible and applicable approach for testing effects of pesticides on bee health. As feeding of a field-realistic pesticide mixture did not elicit acute bee toxic effects, the described differences might be explained by sub-lethal effects or joint action of single compounds.
Highlights
The yield of various crops depends on pollination by bees, among which the honeybees (Apis mellifera Linnaeus 1758) are the most important pollinator species (Klein et al 2007)
We present a methodological approach that so far has not been used for testing the effects of a chronic exposure of pesticide mixtures on the colony level
Pesticides used in rapeseed production but found only in traces below the limit of quantification (LOQ) were considered in their respective concentration at limit of detection (LOD)
Summary
The yield of various crops depends on pollination by bees, among which the honeybees (Apis mellifera Linnaeus 1758) are the most important pollinator species (Klein et al 2007). Electronic supplementary material The online version of this article (doi:10.1007/s13592-016-0479-x) contains supplementary material, which is available to authorized users. Against this background, the uptake of pesticides by foraging bees into the hive and the contamination of food storage is obvious and might cause long-term effects on colony development (Mullin et al 2010). There might be no acute insecticidal effect through such contaminations, various pesticides taken up in sub-lethal concentrations are considered to have negative effects on learning, foraging behavior, or development of individual honeybees (Thompson 2003; Aliouane et al 2009; Dai et al 2010; Wu et al 2011; Williamson et al 2013; Fischer et al 2014; Urlacher et al 2016). Investigations of mixtures of some active substances have confirmed joint actions by additive and/or synergistic effects on physiological processes, often increasing the susceptibility to single pesticides in a pesticide mixture (Pilling et al 1995; Gill et al 2012)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
