Pesticide Science (1999) 55, 626-632

M. Ahmad, M.I. Arif and Z. Ahmad (1999)
Patterns of resistance to organophosphate insecticides in field populations of Helicoverpa armigera in Pakistan
Pesticide Science 55 (6), 626-632
Abstract: The pattern of organophosphate resistance in field populations of Helicoverpa armigera (Hübner) was monitored in Pakistan from 1994 through 1997 using an IRAC leaf-dip method. Generally, moderate to high resistance was found to an orthophosphorate, monocrotophos and to a dithiophosphorate, ethion. Resistance to the commonly used thiophosphorates, chlorpyrifos and profenofos, was very low during 1994 and 1995 but showed an upward trend during 1996 and 1997. Resistance factors to the other thiophosphorates such as quinalphos, parathion-methyl, methamidophos and triazophos remained very low. Baseline lethal concentrations for ethion, methamidophos and triazophos were at least four to five times higher than those for the other organophosphates tested, suggesting their low intrinsic efficacy against H armigera.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Mushtaq Ahmad

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Helicoverpa armigera