Acta Entomologica Sinica (2002) 45, 733-738

Song Chen, Yi-Hua Yang and Yi-Dong Wu (2002)
Frequency distributions of esterase activity and insecticide resistance in third-instar larvae in different strains of Helicoverpa armigera Hübner
Acta Entomologica Sinica 45 (6), 733-738
Abstract: General esterase activity to alpha-NA in two susceptible laboratory strains (Yanshi and Hubei), two lab-selected resistant strains (PCP20 and YG45) and nine field strains of cotton bollworm Helicoverpa armigera Hübner were measured by microtiter plate kinetic assay. Frequency distribution patterns of esterase activity in the Yanshi, Hubei and Shawan susceptible field strains were similar and their mean esterase activities were 991, 1138 and 1055 mOD X min^-1 X larva^-1 respectively. Two lab-selected resistant strains (PCP20, YG45) and three field resistant strains (Yanggu, Handan and Anyang) had many more individuals of high esterase activity (more than 1800 mOD X min^-1 X larva^-1) than three susceptible strains and their mean esterase activities ranged from 1510 to 2482 mOD X min^-1 X larva^-1. Another two field strains (Xuzhou and Wuhan) had moderate-high easterase individuals and their mean esterase activities were 1208 and 1404 mOD min^-1 X larva^-1. The correlation coefficient between mean esterase activity and resistance level was 0.82 to pyrethroids and 0.42 to organophosphates. The same results were obtained when the correlation between the frequency of individuals with high esterase activity and the resistance levels to pyrethriod and organophosphate was analyzed. The results suggested that general esterase activity has some relationship to pyrethroid resistance levels. Because esterase is not a major mechanism for pyrethroid resistance in H. armigera it can only be used as a reference index for the detection of biochemical resistance.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Chinese)
Database assignments for author(s): Yihua Yang

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		China (south)