苦豆子条带对棉田捕食性天敌发生的影响

Effects of Sophora Strips on the Population Occurrence of Predators in Cotton Fields

【目的】研究田埂边苦豆子(Sophora alopecuroides L.)条带对棉田内捕食性天敌发生及其控蚜作用的影响,为棉花生产中田埂合理保留保育天敌的功能性杂草、促进棉田天敌保育与害虫自然控制提供科学依据。【方法】系统调查田边苦豆子条带及棉田天敌与害虫种群,罩笼评价天敌控害功能。【结果】苦豆子与棉花上捕食性天敌种类基本相同、群落结构相似,苦豆子条带上各类主要捕食性天敌的数量均显著高于棉田。处理棉田(棉田边有苦豆子条带)中瓢虫、草蛉、蜘蛛密度分别为对照棉田(棉田边无杂草)的1.3、3.4和4.5倍,发生高峰期较对照棉田提前一周左右。6月上旬和8月,处理棉田的捕食性天敌和蚜虫之间的益害比显著高于对照棉田。处理棉田捕食性天敌对棉蚜控害指数显著高于对照棉田。【结论】苦豆子杂草带对有益天敌具有明显保育作用,能促进棉田捕食性天敌的发生与生物控害。

【Objective】 This study aims to assess the effect of sophora strips on the occurrence of predators and their biocontrol on aphids in cotton fields. It will provide a scientific basis for reserving natural-habitats to benefit natural enemy conservation and pest management in adjacent crop fields.【Method】 Field systematic investigation and exclusive cage experiment were conducted.【Result】The species of the main predators and their community structure in sophora strips were basically similar to those in cotton fields,however, the population densities of these predators in sophora strips were significantly higher than that in cotton fields. The densities of lady beetles, lacewings and spiders in cotton field adjacent sophora strips were 1.3, 3.4 and 4.5 times of those in cotton field without sophora strips, respectively, and the peaks of these predators were about one week earlier than the cotton field without sophora strips. In early June and August, the ratio of predators to aphids in cotton field with sophora strips was significantly higher than that in cotton field without sophora strips. In addition, the biocontrol services index of predators to cotton aphid in cotton field with sophora strips was significantly higher than that in cotton field without sophora strips.【Conclusion】Sophora alopecuroides strip has obvious effects on the conservation of beneficial natural enemies, and can promote the abundance of predators to suppress cotton aphid in adjacent cotton fields. It’s very important to use non-crop habitats such as sophora strips to conserve predatory natural enemies and enhance pest management on cotton aphids in agricultural ecosystem.