Dynamics of pyrethroid resistance in a field population of Helicoverpa armigera (Hübner) in China

✍ Scribed by Han, Zhaojun; Wang, Yinchang; Zhang, Qiansong; Li, Xianchun; Li, Guoqing

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 105 KB
• Volume: 55
• Category: Article
• ISSN: 1526-498X
• DOI: 10.1002/(sici)1096-9063(199904)55:4<462::aid-ps931>3.0.co;2-c

✦ Synopsis

Dynamics of pyrethroid resistance in a üeld population of cotton bollworm (Helicoverpa armigera) was demonstrated by continuous monitoring with twin discriminating dosages, and the inýuencing factors were also experimentally analysed. Resistance in a üeld population in China increased rapidly in the 3rd and 4th generations when population density became higher and insecticides were applied repeatedly, then decreased suddenly during over-wintering and slowly in the 1st and 2nd generations when insecticide spraying was suspended. Resistance increase could be countered by dilution as a result of immigration of susceptible moths from corn üelds, which were found to be a natural refuge for this pest in China. The reduction of resistance during over-wintering and the 1st and 2nd generations was aþ ected by the lower ütness of resistant cotton bollworms to low temperature and disadvantages in reproduction. The possibilities of managing the resistance in üeld populations on the basis of these observations are discussed.