Pesticides turn queens into workers

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Stingless bees (Tetragonisca angustula)

Stingless bees (Tetragonisca angustula) by Bernard DUPONT. Photo licensed under CC BY-SA 2.0.

Pesticides are used in agriculture to combat insects that threaten crop yields and quality. The chemicals used to kill or deter pests, however, are also known to have an impact on beneficial insects providing ecosystem services, such as pollination by honeybees and bumblebees. This study focuses on another group of important pollinators, the stingless bees, for which toxicological pesticide studies are lacking. Investigating the effects of a common pesticide, CPY, on stingless bee larval development, researchers used GBIF-mediated occurrences overlapped with data on use of CPY to determine relevant geographical context. Through in vitro queen-rearing experiments, the researchers discovered that in addition to being lethal at higher doses, CPY at sub-lethal concentrations caused 33 per cent of the larvae to develop into workers rather than queens, and this percentage increased with dose. CPY also increased development time significantly. The authors suggest developing alternative methods of pest control to reduce toxic exposure among beneficial insects.

Citation information 

Dos Santos CF, Acosta AL, Dorneles AL, dos Santos PDS and Blochtein B (2016) Queens become workers: pesticides alter caste differentiation in bees. Scientific Reports. Springer Nature 6(1). Available at doi:10.1038/srep31605