Effects of the release amount of predatory mites on the control of Panonychus citri
In mid September of 2022,in a Orah citrus orchard in the Nujiang Grand Canyon of Lushui City,Yunnan Province,the population dynamics of Panonychus citri were investigated in the areas of different pop-ulation densities(≤ 15 heads/plant,25-55 heads/plant,and ≥ 95 heads/plant)after releasing 1 bag of predatory mites(≥ 3 000 heads of pesticide-resistant Bacteroidetes)and 2 bags(≥ 6 000 heads of pesticide-resistant Bacteroidetes)per plant,respectively,with non-releasing predatory mites as the control group.The control effect of releasing predatory mites on P.citri was also analyzed.The results showed that in the area where the number of P.citri was ≤15 heads per plant,there was no significant difference in the population of P.citri between releasing 1 bag and 2 bags of predatory mites per plant,but there was a significant differ-ence compared with the control group.In the area with 25-55 heads/plant of citrus red mites,the population of citrus red mites in the treatment of releasing 2 bags of predatory mites per plant was significantly lower than that of releasing 1 bag,and the population of citrus red mites in the areas of predatory mites released was sig-nificantly lower than that of the control group.In the area with ≥ 95 heads/plant of P.citri,the populations of P.citri of two predatory mite releasing treatments showed a decreasing trend,with the population of P.citri in one bag releasing decreased at a slower rate than that in two bags releasing.In areas with less than or equal to 15 citrus mites per plant,releasing 1 bag per plant or 2 bags per plant of predatory mites could achieve good control effects.However,considering the cost of prevention and control,it was recommended to release 1 bag per plant.In the area with 25-55 heads/plant of P.citri,releasing 2 bags/plant of predatory mites had a good control effect of over(84.19±4.99)％from the 28th day to the 63th day of treatment.In areas where the number of citrus red mite was ≥ 95 heads per plant,the effectiveness of releasing predatory mites to con-trol citrus red mites was low.It was advisable to firstly use pesticides to reduce the population base of citrus red mites before releasing predatory mites.
万方数据
维普
