Effects of imidacloprid and deltamethrin on associative learning in honeybees under semi-field and laboratory conditions.
We have compared the sublethal effects of two insecticides in the honeybee (imidacloprid and deltamethrin) in both semi-field and laboratory conditions. A sugar solution containing 24 microg kg(-1) of imidacloprid or 500 microg kg(-1) of deltamethrin was offered to a colony set in an outdoor flight cage. In contrast to imidacloprid, deltamethrin had lethal effect on workers bees. The contamination of syrup with imidacloprid or deltamethrin induced a decrease in both the foraging activity on the food source and activity at the hive entrance. Negative effects of imidacloprid were also observed in an olfactory learnt discrimination task. Free-flying foragers were taken from the contaminated feeder and subjected to a conditioned proboscis extension response (PER) assay under laboratory conditions. As with free-flying bees, no impact of deltamethrin was found on the learning performances of restrained individuals in the PER procedure, whilst significant effects were found with imidacloprid in both semi-field and laboratory conditions.
Decourtye
Axel
A
Laboratoire de Neurobiologie Comparée des Invertébrés, INRA, BP 23, 91440 Bures-sur-Yvette, France.
Devillers
James
J
Cluzeau
Sophie
S
Charreton
Mercedes
M
Pham-Delègue
Minh-Hà
MH
D000818:Animals; D001516:Bees; D004193:Discrimination Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior; D005260:Female; D007093:Imidazoles / Q000633:toxicity*; D007306:Insecticides / Q000633:toxicity*; D008297:Male; D000073943:Neonicotinoids; D009570:Nitriles; D009574:Nitro Compounds; D011722:Pyrethrins / Q000633:toxicity*; D012903:Smell
D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009570:Nitriles; D009574:Nitro Compounds; D011722:Pyrethrins; C017180:decamethrin; C082359:imidacloprid