Abstract:
The frequencies of alleles for kdr type resistance to cyhalothrin in field populations of Helicoverpa armigera collected from Xinjiang and North China were evaluated by single-pair mating and hot-probe method. It was found that there was no individual of kdr-type resistance, including heterozygote of resistant gene, in the population of Xinjiang.The frequencies of alleles for kdr-type resistance to cyhalothrin were estimated as 20.83% and 11.11% in JF1 and JF2population, respectively. The results indicated that Xinjiang population was still suscepitible, however, kdr-type resistance had developed at high level in Jizhou population. The results also showed that most of resistant individuals were heterozygotes, but a few were homozygous resistant in JF1 population.