Cockroach density and Blattella germanica insecticide resistance in Huangpu District of Shanghai in 2022
Objective To understand the cockroach population composition,density,and Blattella germanica resistance to three commonly used insecticides in Huangpu District of Shanghai,and provide scientific basis for the prevention and control of Blattella germanica.Methods The sticky trap method was adopted for cockroach density investigation,while the film contact method insecticide resistance test.Results A total of 1 200 pieces of sticky cockroach paper were placed in Huangpu District from January to December 2022,with 1139 effective and 49 positive.The trapping rate was 4.30%,and 253 cockroaches including 248 Blattella germanica,3 Periplaneta fuliginosa and 2 Periplaneta americana,were captured with a total density of 0.22 cockroaches per night.The monitoring results showed significant differences in the cockroach densities in different ecological environments,highest in agricultural markets,followed by small and medium-sized catering institutions.The resistance test showed that the KT50s of cypermethrin,acephate and propoxur were 213.51,155.36 and 96.02 minutes to the field population of Blattella germanica collected in Huangpu District,and 90.09,3.84,and 8.45 folds resistance developed,respectively.Conclusion Blattella germanica developed some resistance to the commonly used insecticides,and was the key object in cockroach control in Huangpu District.