Institut für Bienenkunde, Polytechnische Gesellschaft
Goethe-Universität Frankfurt am Main, FB Biowissenschaften
Neonicotinoid insecticides act as agonists of the insect nicotinic acetylcholine receptor. Applications of sublethal insecticide doses lead to various motor abnormalities in honeybees. Here, we investigated the effects of clothianidin, imidacloprid, or thiacloprid on the motor activity of bees. In a first approach we monitored their movement in a small arena before and after being fed with sugar water containing clothianidin or thiacloprid. We observed increased motor activity after clothianidin and a decreased activity after thiacloprid-treatment.
To analyze the effects on motor activity we recorded electromyograms of the muscle M17 before and during insecticide perfusion. Muscle spikes and proboscis extension reactions were elicited by stimulating the antennae and the proboscis with sugar solution. We investigated neonicotinoid-induced changes by determining spikes at different intervals after substance application. Insecticide or phosphate-buffered saline was pipetted onto the brain. Our results showed that clothianidin increased the muscle activity and in some animals even led to continuous spiking without sugar stimulation. By contrast, imidacloprid and thiacloprid reduced the spike activity during the whole recording period (1h). Our results, although preliminary, indicate distinct effects of the various insecticides on honeybee motor activity. Tone of the next steps will be to study, whether neonicotinoids act on neurons, muscles or both.
since 2011 PhD student at the Institute for Bee Research Oberursel (Polytechnic Society) / (Goethe University Frankfurt)
PhD thesis: Cholinergic synaptic transmission in the honeybee’s olfactory system and effects of insecticides
2004 – 2010 Studies in Biology (main subject: zoology, minor subjects: ecology, psychology), University of Bremen (Germany)
Diploma thesis: „Sucrose sensitivity and collecting behaviour of the Indian dwarf honeybee Apis florea“
(conducted in Bangalore, India)
2001 – 2004 BA in Modern Languages and Cultural Mediation, Danish/English, University of Southern Denmark in Sønderborg (Denmark)
Degree: Bachelor of Arts
- Triltsch, M.; Fischer, J.; Grünewald, B. (2012) Effects of neonicotinoid insecticides on the spike frequency of the honeybee proboscis muscle M17. IN:
proceedings of the 59th annual meeting, association of the institutes for bee research, Bonn, Germany
- Triltsch, M.; Fischer, J.; Kabat vel Job, K.; Grünewald, B. (2012) Effects of neonicotinoid insecticides on the muscle activity of the honeybee. IN:
Eurbee 5th European Conference of Apidology, Halle, Germany