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1978到1981年,作者在陕西武功查清了棉田食蚜天敌主要有12类,分属8目、16科、39种。采用将食蚜天敌个体捕食或寄生寄主的功能反应与大田中食蚜天敌的数量反应相结合的方法, 以统一的天敌单位数表示各类天敌作用的大小。四年平均每年每亩食蚜天敌约100万头次,折合天敌单位数为42071。各美食蚜天敌按其作用大小依次为:瓢虫、蜘蛛、蚜霉菌、食蚜蝇、草蛉、食蚜绒螨、花蝽、姬猎蝽、蚜茧蜂、食蚜盲蝽等。不同季节天敌种类不同,瓢虫和蜘蛛是季节稳定种,食蚜绒螨和蚜霉菌是季节发生种,以上均为棉蚜关键性天敌。棉蚜的种群数量水平,明显的受食蚜天敌的自然控制。在棉花苗期,由于天敌的作用,无蚜期可维持15至20天。八月份如多雨潮湿,蚜霉菌可完全控制伏蚜为害。
From 1978 to 1981, the author identified 12 predators of the aphid in the cotton field in Wuchang, Shaanxi, belonging to 8 orders, 16 families and 39 species. The method of combining the functional response of the host predatory or parasitic host with the natural enemies of aphis in the field was used to express the effect of various natural enemies on the unit number of the natural enemies. The average annual number of natural enemies of aphids per acre is about 1 million times per year for four years, which is equivalent to 42071 natural enemy units. Each aphid natural enemies according to their role in the order of size: ladybugs, spiders, aphids, hoverflies, grass mulberry, aphid mites, stinkbugs, bugs assassin, aphid Braconidae, aphid Apis mellifera. Different species of natural enemies in different seasons, ladybugs and spiders are seasonal species, aphid mites and aphids are seasonal occurrences, all of which are the key natural enemies of cotton aphids. The population level of cotton aphid is apparently controlled by natural enemies of the food aphid. In the cotton seedling stage, the aphid stage can be maintained for 15 to 20 days due to natural enemies. In August, when wet and humid, the aphid can completely control the aphid infestation.