Acta Entomologica Sinica (1996) 39, 347-353

Yong Zhao, Anxi Liu, Lijun Ru, Xianlin Fan and gen Wei (1996)
[Decreased nerve sensitivity is an important pyrethroid resistance mechanism of cotton bollworm]
Acta Entomologica Sinica 39 (4), 347-353
Abstract: The morphology of the 3rd instar larval cotton bollworm (Helicoverpa armigera Hübner) ventral nerve and muscle was studied by scanning electron and light microscopes. The results of observation showed that all of the ventral longitudinal muscle cells are suitable for the electrophysiological intracellular recording. The nerve sensitivity to the corresponding pesticides of 3rd instar larval neuromuscular synapses of three strains of the cotton bollworm including the control, the cyhalothrin resistant (Cy-R, resistance ratio: 13.4) and the fenvalerate resistant (Fn-R, resistance ratio: 37.9) strains was studied by using the electrophysiological intracellular microelectrode recording technique. The results showed that when Cy-R was treated by 10^-6 mol/L cyhalothrin, 60% individuals had the repetitive discharge within 30 min; however, the reaction time was 3.5 times as much as that of the control. And the other 40% individuals had no reaction. When Fn-R was treated by 10^-6 mol/L fenvalerate, 53% individuals had the repetitive burst discharge within 30 min, however, the reaction time was 4.2 times as much as that of the control. And the other 47% individuals had no reaction. It implies that the decreased nerve sensitivity is an important pyrethroid resistance mechanism of cotton bollworm.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Chinese)

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