A common neonicotinoid pesticide, thiamethoxam, impairs honey bee flight ability

Simone Tosi,Giovanni Burgio,James C Nieh

doi:10.1038/s41598-017-01361-8

Abstract

Pesticides can pose environmental risks, and a common neonicotinoid pesticide, thiamethoxam, decreases homing success in honey bees. Neonicotinoids can alter bee navigation, but we present the first evidence that neonicotinoid exposure alone can impair the physical ability of bees to fly. We tested the effects of acute or chronic exposure to thiamethoxam on the flight ability of foragers in flight mills. Within 1 h of consuming a single sublethal dose (1.34 ng/bee), foragers showed excitation and significantly increased flight duration (+78%) and distance (+72%). Chronic exposure significantly decreased flight duration (−54%), distance (−56%), and average velocity (−7%) after either one or two days of continuous exposure that resulted in bees ingesting field-relevant thiamethoxam doses of 1.96–2.90 ng/bee/day. These results provide the first demonstration that acute or chronic exposure to a neonicotinoid alone can significantly alter bee flight. Such exposure may impair foraging and homing, which are vital to normal colony function and ecosystem services.

Highlights

Pollinators play an important environmental role by providing essential ecosystem services[1]
We focused on thiamethoxam (TMX), a second generation neonicotinoid that is widely used[5] and persistent[6], and is frequently found in multiple environmental substrates such as nectar, pollen, guttation, water, and bee hives[6, 23,24,25]
TMX can alter forager flight muscle temperature[28], and the results of Henry et al.[16, 17] suggested that TMX could impair honey bee flight: we focused on TMX, using tethered bees flying on flight mills to test their physical ability to fly[29,30,31,32,33], measuring flight distance, duration, and velocity in exposed and control bees

Summary

Introduction

Pollinators play an important environmental role by providing essential ecosystem services[1]. Exposure to even low concentrations of neonicotinoids can harm bee health via synergistic interactions between multiple stressors[3, 7, 8] Neonicotinoids and their degradation products are agonists of insect nicotinic acetylcholine receptors[5] and have a wide variety of neural effects[8, 9]. These compounds can harm bee foraging[10,11,12,13], homing[14,15,16,17], locomotion[18, 19], navigation[20], and colony health[17]. TMX can alter forager flight muscle temperature[28], and the results of Henry et al.[16, 17] suggested that TMX could impair honey bee flight: we focused on TMX, using tethered bees flying on flight mills to test their physical ability to fly[29,30,31,32,33], measuring flight distance, duration, and velocity in exposed and control bees

Methods

Results

Conclusion