Abstract:

To understand the occurrence dynamics of Aphis gossypii, and improve a pesticide-reduction technology against aphids, we carried out monitoring, investigation and trials in the watermelon and muskmelon greenhouses of Liaoning Province. Yellow sticky boards were applied to monitor the occurrence dynamics of A. gossypii in the greenhouses, and systematic investigations and pesticide efficacy trials with two reagents mixed were implemented. The results showed that the peak of winged aphids occurred in early-March in muskmelon cultivar ‘Cuibao’ greenhouses of Datun town, Beizhen City, and the peak of total aphids was in the end of February; the winged aphids reached peak in mid-May in watermelon cultivar ‘Tianwang’ greenhouses of Xiongyue town, Yingkou City, and the peak of total aphids was in early-May; the peak of winged aphids occurred in late-May in watermelon cultivar ‘Tianwang’ greenhouses of Dapu Mongolian town, Fengcheng City, and the peak of total aphids was in mid-May. Compared with the control, the new type high-fat membrane powder could significantly improve the control effect of 25% thiamethoxam water dispersible granule (WG) against A. gossypii, and the control effect after 14 days’ treatment could reach 97.0%. The critical period for the control and prevention of A. gossypii in muskmelon cultivar ‘Cuibao’ greenhouses and watermelon cultivar ‘Tianwang’ greenhouses is late-February and early and mid-May respectively, which could achieve good efficacy and have low cost.

Key words: Aphis gossypii, greenhouse, population dynamics, the critical period for control and prevention, new type high-fat membrane