关键词: 滞留喷洒, 溴氰菊酯, 德国小蠊, 击倒抗性, 基因型

Abstract: Objective To determine the residual spray effect of deltamethrin on German cockroach (Blattella germanica) and the potential relationship between the kdr mutation and the resistance. Methods The resistance ratio of the two field strain B. germanica to deltamethrin was detected by residual contact (glass jar). The forced contact test was conducted to detect the residual spray effect on 3 representative panels of glass, painted wood and cement. The kdr genotype was determined by sequencing. Results The knockdown rate decreased with the increase in the surface water absorption, with the duration of efficacy shortened. The killing effect of the insecticide varied with the resistance status of different strains. The 3 panels were all able to kill the susceptible and low resistance strains effectively, but had no reliable effect on the strain with moderate resistance. Low and moderate resistant field strains that were tolerant to deltamethrin all had the kdr genotype, with the former having a relatively high frequency of heterozygosis genotype (RS), the latter relatively high in the homozygosis genotype (RR). Conclusion B. germanica resistance to deltamethrin residual spray was closely related to the kdr genotypes. Incorrect use of insecticide may result in the increase of kdr genotype frequency, so frequency and dosage need to be adjusted based on the environment types, the target resistance and the insecticide history with residual spray management combined with toxic or gel bait to achieve the ideal control effect.

Key words: Residual spray, Deltamethrin, Blattella germanica, kdr, Genotype