Journal of Insect Behavior (2013) 26, 1-13

Jefferson P. Galvanho, Marinete P. Carrera, Denise D.O. Moreira, Milton Erthal Jr., Carlos P. Silva and Richard Ian Samuels (2013)
Imidacloprid inhibits behavioral defences of the leaf-cutting ant Acromyrmex subterraneus subterraneus (Hymenoptera:Formicidae)
Journal of Insect Behavior 26 (1), 1-13
Abstract: Leaf-cutting ants have evolved a range of defensive strategies which complicate the use of entomopathogens for their control. One of these behavioral strategies is self-grooming, which increases when ants detect the presence of fungal conidia on their integuments. We have previously shown that insecticides, when used at ultra-low concentrations, can be synergists of entomopathogenic fungi. It is possible that certain insecticides could modify ant behavior in a way that increases the chances of a fungal infection taking hold. The current study investigated the effects of the neonicotinoid insecticide Imidacloprid (IMI) and the entomopathogenic fungus Beauveria bassiana on self-grooming and locomotion behavior of Acromrymex subterraneus subterraneus workers when ants were exposed to the agents separately or together. Initially 10, 20 and 40 ng/insect IMI was topically administered to worker ants. Four hours after administration, the ants were placed into an experimental arena and self-grooming and locomotion behaviors were recorded for 10 min. Separate groups of ants were exposed to filter paper discs impregnated with conidial suspensions and 4 h later their behavior was monitored for 10 min. Subsequently, ants were treated with 10 ng/insect IMI, immediately exposed to fungal suspensions and 4 h later their behavior was monitored. The 10 ng/insect IMI treatment resulted in higher locomotor activity and lower self-grooming when compared to vehicle, 20 ng and 40 ng IMI treatments. Exposure to fungal conidia produced low locomotion and high self-grooming behaviors. The 10 ng IMI + fungal conidia treatment resulted in lower self-grooming and higher locomotion behavior. These alterations caused by a low concentration of IMI could increase ant susceptibility to infection by entomopathogenic fungi and are thus of interest for future tests in the development of integrated pest management strategies.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
control - general
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
application technology
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Acromyrmex subterraneus
Beauveria bassiana (entomopathogen)	Acromyrmex subterraneus