Abstract:
【Aim】 This study aims to explore the conditions for improving the fumigation effect and efficiency of dichlorvos smoke agent in controlling Bradysia odoriphaga adults. 【Methods】 Four factors including temperature, relative humidity, period and dosage were optimized by the orthogonal experiment, and the fitted model was established by multiple regression analysis and verified by a set of experiments. 【Results】 The main effect analysis of the orthogonal experiment results showed that the influence order on the efficacy of dichlorvos smoke agent was dosage>temperature>relative humidity>period. Determined by analysis of variance and multiple comparison, the optimal conditions for fumigation were the temperature of 32℃, relative humidity of 70%, dosage of 0.0878 g a.i./m³ and period of 2 h. Regression analysis showed that there were interactions between temperature and relative humidity, temperature and dosage, and relative humidity and dosage, with the interaction effect indices of 3, -4.4 and -3.25, respectively. At the same time, the regression equation of the mortality of test insects and the related factors was established. The mortality under the optimized fumigation conditions was 96.59%. Moreover, the Pearson’s correlation coefficient between the measured value and the predictive value was 0.9749, showing that the regression model was verified to be accurate and effective by the experiments. 【Conclusion】 The control efficacy of dichlorvos smoke agent in controlling B. odoriphaga adults can be promoted by optimizing fumigation conditions, and the regression model obtained in this study can be used to predict the mortality of B. odoriphaga adults.

Key words: Bradysia odoriphaga, dichlorvos smoke agent, orthogonal experiment, variance analysis, multiple regression analysis