利用食蚜瘿蚊防治保护地蔬菜桃蚜的试验

在蔬菜温室、弓棚、大棚内释放食蚜瘿蚊防治桃蚜,当单株蚜量在200头以下时,以1:20益害比释放瘿蚊成虫,9～12天后温室、弓棚内桃蚜分别减退75.1％～91.8％和80.1％～90.5％。1990年在5个大棚内以1:20益害比,一次释放,10天后蚜虫减退82.2％,30天后蚜虫有所回升,单株蚜量141.2头。1991年6～7月份,在16个大棚内分别释放瘿蚊,当单株蚜虫146头时,按1:20益害比,在2周内分2～3次释放瘿蚊,10天后单株蚜量减退86.4％,以后蚜虫仍逐日下降,在拉秧前60天内能有效地控制蚜害,不需使用化学农药。

TESTS ON THE EFFECT OF RELEASING APHIDOLETES APHIDIMYZA [DIP.: CECIDOMYIIDAE] TO CONTROL THE APHID, MYZUS PEESICAE IN GREENHOUSES AND PLASTIC TUNNELS

. Experiments were carried out during 1990-1991 in the greenhouses and two typical types of plastic tunnels for vegetable production in Daqing, Helongjiang Province on the control of the aphid Myzus persicae by inundative releases of mass reared aphid midge, Aphidoletes aphidimyza. Releasing the predator at a predator:prey ratio of 1:20 when the aphid population reached 200 aphids/plant in the greenhouse and the small sized tunnel reduced the aphid populations by 75.1-91.8% and 80.1-90.5%, respectively, 9-12 days after the release. In 1990, a single release was made in 5 large sized tunnels, respectively, at the predator:prey ratio of 1:20. The aphid population reduction was 82.2% 10 days after the release. The aphid population was suppressed below 141.2-150.5 aphids/plant for 30 days. During June-July, 1991, releases were made on pepper in 16 large sized tunnels at same ratio but in 2-3 releases during two weeks period, with 86.4% reduction of the aphid population 10 days after the last release. The aphid populations continued to decline and were effectively suppressed for 60 days till removal of the first planting crcp, during which period, no additional insecticide application was needed.