Effects of weather parameters on the population dynamics of Megalurothrips usitatus in cowpea fields in Sanya, China

In order to clarify the population dynamics of Megalurothrips usitatus (Bagnall) in cowpea field and its relationship with weather parameters in Sanya. Population density of M. usitatus monitored by blue plate trapping method in cowpea field for two consecutive years. Correlation analysis, stepwise regression analysis, path analysis, grey relation analysis, and redundancy analysis were used to analyze the relationship between population density and weather parameters. The results showed that the peak of population density was the flowering period of cowpea, which period was the main activity period of M. usitatus. Correlation analysis showed that the population change of summer crop was related to temperature, wind speed and precipitation, and winter crop was related to temperature. Redundancy analysis showed that temperature of summer crop combined to affect the population density of M. usitatus. The temperature and humidity during winter crop affected the population density of M. usitatus. Regression analysis showed that the population density of summer and winter thrips were most affected by daily average temperature. Grey relation analysis showed that the annual occurrence of the M. usitatus was affected by the combined temperature and precipitation. These results will contribute to predicting the changes that may occur in a population of M. usitatus concerning the weather parameters.