Fatal powdering of bees in flight with particulates of neonicotinoids seed coating and humidity implication
Article first published online: 21 JUN 2011
© 2011 Blackwell Verlag, GmbH
Journal of Applied Entomology
Volume 136, Issue 1-2, pages 17–26, February 2012
How to Cite
Girolami, V., Marzaro, M., Vivan, L., Mazzon, L., Greatti, M., Giorio, C., Marton, D. and Tapparo, A. (2012), Fatal powdering of bees in flight with particulates of neonicotinoids seed coating and humidity implication. Journal of Applied Entomology, 136: 17–26. doi: 10.1111/j.1439-0418.2011.01648.x
- Issue published online: 6 JAN 2012
- Article first published online: 21 JUN 2011
- Received: February 23, 2011; accepted: May 19, 2011.
- Apis mellifera;
- colony losses;
- corn dressing;
Losses of honeybees have been reported in Italy concurrent with the sowing of corn coated with neonicotinoids using a pneumatic drilling machine. Being unconvinced that solid particles containing systemic insecticide, falling on the vegetation surrounding the sown area, could poison bees foraging on contaminated nectar and pollen, the effect of direct aerial powdering was tested on foragers in free flight near the drilling machine. Bees were conditioned to visit a dispenser of sugar solution whilst a drilling machine was sowing corn along the flight path. Samples of bees were captured on the dispenser, caged and held in the laboratory. Chemical analysis showed some hundred nanograms of insecticide per bee. Nevertheless, caged bees, previously contaminated in flight, died only if kept in conditions of high humidity. After the sowing, an increase in bee mortality in front of the hives was also observed. Spring bee losses, which corresponded with the sowing of corn-coated seed, seemed to be related to the casual encountering of drilling machine during foraging flight across the ploughed fields.