人工释放2种天敌昆虫的防治效果及其对烟田天敌昆虫种群的影响

为有效评价两种天敌昆虫烟蚜茧蜂和捕食螨对烟蚜和烟蓟马的防治效果，在四川攀枝花米易烟区连续两年开展了生物防治研究。分别采用烟蚜茧蜂、捕食螨和吡虫啉处理后，调查分析生物防治措施对田间害虫和主要天敌昆虫种群的作用。研究结果表明：（1）烟蚜茧蜂和捕食螨在前期对烟蚜和烟蓟马的防控效果分别为6.18%和33.94%，后期防治效果分别为55.38%和65.00%；吡虫啉防治效果与之相反。（2）烟蚜茧蜂和捕食螨分别使田间昆虫天敌种群数量下降了25.12%和20.02%，远低于吡虫啉的影响（ 53.29%）。其中对食蚜蝇影响最大，分别为39.36%和51.85%，对瓢虫类为20.77%和 1.57%，对蜘蛛类为12.46%和1.60%。因此，释放烟蚜茧蜂和捕食螨可用于烟蚜和烟蓟马的长期防控，且对烟田昆虫天敌生态系统友好，具有较好的推广应用价值。

Control Effects of Two Released Natural Enemy Insects and Their Effect on Natural Enemy Populations in Tobacco Fields

The biological control efficacy against Myzus persicae (Sulzer) and Thrips tabaci (Lindeman) was evaluated by releasing Aphidius gifuensis (Ashmead) and Neoseiulus barkeri (Hughes) into a tobacco field in Miyi, Panzhihua, Sichuan Province, for two years. The effect on tobacco aphids, thrips, and other insects was assessed during the presence of the released natural enemy insects.The results showed that:the control effect of Aphidius gifuensis against Myzus persicae and Neoseiulus barkeri against Myzus persicae was 6.18% and 33.94% in the earlier stage, respectively, and increased to 55.38% and 65.00% later on. However, the effect of imidacloprid treatment was the opposite.Both Aphidius gifuensis and Neoseiulus barkeri had reduced the populations of other insects in the field to 25.12% and 20.02%, respectively, which were far lower than the effect of imidacloprid (53.29%). The population of Syrphidae was most affected with reductions of 39.36% and 51.85%, followed by Coccinella with reductions of 20.77% and 1.57%, while spiders were minimally affected at 12.46% and 1.60% by the natural enemy insects.This study indicates that Aphidius gifuensis and Neoseiulus barkeri are eco friendly and highly effective for the long term control of tobacco aphids and thrips. Bio control technologies like these could be applied in the future.