Experimental and Applied Acarology (2009) 49, 185-192

Jahangir Khajehali, Thomas Van Leeuwen and Luc Tirry (2009)
Susceptibility of an organophosphate resistant strain of the two-spotted spider mite (Tetranychus urticae) to mixtures of bifenazate with organophosphate and carbamate insecticides
Experimental and Applied Acarology 49 (3), 185-192
Abstract: Bifenazate, a new and frequently used carbazate, is a pro-acaricide which needs to be activated by carboxylesterases. We evaluated the possible antagonism of organophosphate and carbamate insecticides on bifenazate toxicity in Tetranychus urticae applied in mixtures. Two organophosphate resistant strains were used (WI and MR-VL) and several organophosphate (chlorpyrifos, azinphosmethyl and phosmet) and carbamate (carbaryl and methomyl) insecticides were evaluated. Mixing chlorpyrifos with bifenazate decreased bifenazate toxicity in both tested strains. However, in the strain with a higher esterase activity, antagonism decreased after 2 days. Of all other tested chemicals, only methomyl displayed an antagonistic effect 1 day after treatment. These findings indicate that mixing organophosphate and carbamate insecticides with bifenazate may inhibit bifenazate efficacy under field conditions, especially when resistant strains are present.
(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): Thomas Van Leeuwen, Luc Tirry

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tetranychus urticae