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近年由于生态环境的变化及感蚜品种种植面积的扩大,玉米蚜虫逐年严重。如都安县大发生年,全县受害面积达20多万亩,占玉米总面积的35%;78年早造玉米,全县平均蚜株率29.1%,严重田块蚜株率达100%,对玉米生产为害很大。过去,防治玉米蚜虫多采用穗期喷雾法,对害虫天敌杀伤很大,用1000—3000倍的乐果或磷胺,瓢虫的平均死亡率达54.4%以
In recent years, due to changes in the ecological environment and the expansion of aphid varieties planted area, corn aphids year after year serious. For example, in the great occurrence of Du’an County, the affected area of the county reached more than 20 million mu, accounting for 35% of the total corn area. As early as 78 years ago, the average rate of aphids in the county was 29.1%, and that of serious aphids was 100% Harmful to corn production. In the past, the prevention and treatment of maize aphids and more spikes spray method, killing a large number of natural enemies of pests, with 1000-3000 times dimethoate or phosphinamide, ladybug average mortality rate of 54.4%