Sublethal neonicotinoid exposure attenuates the effects of electromagnetic fields on honey bee flight and learning

Abstract

Overview

Many environmental stressors are implicating in the decline of flying insects, particularly important pollinators like the honey bee. Among these, the effects of electromagnetic fields (EMFs) have increasingly become a subject of concern.

Findings

• Research indicates that extremely low-frequency electromagnetic fields (ELF EMFs) could influence insect behavior and cognition, which might interact with other stressors like neonicotinoid insecticides leading to severe impacts on insect populations.
• The study examined honey bees exposed individually and in combination to 50 Hz EMFs and sublethal doses of the insecticide clothianidin through a tethered flight assay and an olfactory appetitive learning assay.
• Clothianidin proved highly toxic, with exposure resulting in a 25% mortality rate in bees at a concentration of 2.00 ng/bee.
• EMFs alone increased wingbeat frequency above 100 µT, while prior exposure to clothianidin moderated this effect.
• Similarly, EMF exposure reduced learning performance measured via the proboscis extension reflex (PER), but this was lessened with prior clothianidin exposure.

Conclusion

No synergistic interaction was recorded between clothianidin and ELF EMFs as environmental stressors. However, the singular potential of EMFs to influence insect populations, particularly those already susceptible due to exposure to insecticides like clothianidin, warrants further exploration.