Journal of Economic Entomology (2011) 104, 773-781

Nilima Prabhaker, Steven J. Castle, Steven E. Naranjo, Nick C. Toscano and Joseph G. Morse (2011)
Compatibility of two systemic neonicotinoids, imidacloprid and thiamethoxam, with various natural enemies of agricultural pests
Journal of Economic Entomology 104 (3), 773-781
Abstract: Two systemic neonicotinoids, imidacloprid and thiamethoxam, are widely used for residual control of several insect pests in cotton (Gossypium spp.), vegetables, and citrus (Citrus spp.). We evaluated their impact on six species of beneficial arthropods, including four parasitoid species-Aphytis melinus Debach, Gonatocerus ashmeadi Girault, Eretmocerus eremicus Rose and Zolnerowich, and Encarsia formosa Gahan-and two generalist predators-Geocoris punctipes (Say) and Orius insidiosus (Say)-in the laboratory by using a systemic uptake bioassay. Exposure to systemically treated leaves of both neonicotinoids had negative effects on adult survival in all four parasitoids, with higher potency against A. melinus as indicated by a low LC₅₀. Mortality was also high for G. ashmeadi, E. eremicus, and E. formosa after exposure to both compounds but only after 48 h posttreatment. The two predators G. punctipes and O. insidiosus were variably susceptible to imidacloprid and thiamethoxam after 96-h exposure. However, toxicity to these predators may be related to their feeding on foliage and not just contact with surface residues. Our laboratory results contradict suggestions of little impact of these systemic neonicotinoids on parasitoids or predators but field studies will be needed to better quantify the levels of such impacts under natural conditions.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Nilima Prabhaker, Steven J. Castle, Steven E. Naranjo

Research topic(s) for pests/diseases/weeds:
control - general
health/environmental effects of pesticides
Research topic(s) for beneficials or antagonists:
resistance to pesticides

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Homalodisca lacerta		U.S.A. (SW)
	Homalodisca vitripennis		U.S.A. (SW)
Encarsia formosa (parasitoid)
Eretmocerus eremicus (parasitoid)
Orius insidiosus (predator)
Geocoris punctipes (predator)
Aphytis melinus (parasitoid)
Cosmocomoidea ashmeadi (parasitoid)	Homalodisca vitripennis		U.S.A. (SW)