Monitoring of cockroaches population and insecticide resistance in Suzhou in 2022
Objective To investigate the population composition in different habitats,seasonal dynamic of cockroaches and resistance level of Blattella germanica in Suzhou.Methods Sticking trap method was used to investigate the density of cockroaches,and the residual film method was used to monitoring the insecticide resistance of Blattella germanica.Results In 2022,the adhesion rate of cockroaches and the density in Suzhou were respectively 7.20%and 0.40 insects per sheet.Blattella germanica accounted for 94.24%was the dominant species.The highest adhesion rate and density in July were 9.73%and 0.56 insects per sheet,respectively.The highest cockroaches density was in the farm product markets which was 1.80 insects per sheet.There was a significant correlation between the overall cockroaches density and the cockroaches density in in the farm product markets in different months(r=0.965,P=0.002).The adhesion rate of cockroaches in different habitats was statistically significant(χ2=483.489,P<0.001).The resistance ratios to beta-cypermethrin,deltamethrin,acephate,chlorpyrifos and propoxur were 3.36,6.18,1.08,1.79 and 0.79,respectively.Conclusion Blattella germanica was the dominant species of cockroaches in Suzhou,and the cockroaches density in the farm product markets is the highest.July is the peak month of cockroaches density.The resistance of Blattella Germanica to deltamethrin is medium resistance,and the resistance to other 4 insecticides is low resistance.