The effects of a fungicide on honeybee queen egg laying rates

The honey bee (Apis mellifera) is important for agricultural production and maintenance. Agroecosystems are maintained by applying pesticides to protect crops from pests and pathogens. However, several pesticides have been shown to adversely affect non-target pollinators, including honey bees. Among pesticides, fungicides may be particularly dangerous for pollinators as they are less regulated and can be applied during crop bloom. The widely used fungicide formulation Pristine ® (ai: boscalid, pyraclostrobin) reduces colony size by impairing worker cognition and reducing lifespan. Despite the pronounced effects of exposure on honey bee workers, the direct impact of Pristine ® on honey bee reproductives is poorly understood. To assess the effects of Pristine ® fungicide on reproductive fitness we maintained honey bee queens in laboratory cages and exposed them to field-realistic concentrations of the fungicide. Fungicide-treated queens are expected to exhibit reduced egg-laying rates, additionally, accompanying workers will exhibit altered pollen consumption rates and reduced hypopharyngeal glands. These outcomes may suggest further mechanisms by which fungicides impact bee health.