Experimental Study
SUN Chun-wei, ZHANG Jie, LIU Yao, ZHOU Yi-bin
Objective To investigate the spatial distribution of Blattella germanica and Periplaneta fuliginosa in a farmers'market in Shanghai,China,and to analyze whether the two cockroach species coexist in the farmers'market and the coexistence characteristics.Methods The population density of cockroaches was monitored once a month from June 2020 to May 2021 by using the sticky trap method (placing a glue trap under an electronic scale at each stall,and inspecting it after 72 hours) in the farmers'market.The data were analyzed using Spearman correlation analysis,Pearson's Chi-square test,spatial analysis,hotspot analysis,and bivariate global spatial correlation analysis.Results The species of cockroaches in the farmers'market included B.germanica and P.fuliginosa.B.germanica was the dominant species,accounting for 94.57% of the total catches.The seasonal changes in the densities of B.germanica and P.fuliginosa were positively correlated (r=0.763,P=0.004).The stalls selling chilled and fresh meat and poultry had the highest infestation rates of B.germanica and P.fuliginosa,which were 29.08% and 6.97%,respectively.There was a positive correlation between the numbers of B.germanica and P.fuliginosa captured at all stalls (r=0.432,P<0.001).The positive rate distribution and density distribution of B.germanica and P.fuliginosa were positively correlated;The bivariate global Morans'Ⅰ index of the positive times of the two species of cockroaches was 0.178(Z=6.786,P<0.001),showing a spatial positive correlation distribution trend;The bivariate global Morans'Ⅰ index of their capture number was 0.127(Z=5.021,P<0.001).Conclusion B.germanica and P.fuliginosa may have similar adaptability to temperature and humidity.The two cockroach species may coexist and compete in the farmers'market,and B.germanica is the competitively dominant species.The control of cockroaches should be considered based on the spatial distribution characteristics of cockroaches in a specific area to formulate targeted control strategies against regional dominant species.