不同施药方式下吡虫啉对棉田绿盲蝽种群动态的影响

为探讨吡虫啉对绿盲蝽种群数量的控制作用，2011—2012年连续两年采用种子包衣、颗粒剂穴施和灌根处理棉花，并结合种植绿豆诱集带的方式，研究其对棉田绿盲蝽种群动态的影响。在吡虫啉有效成分用量为1 500 g/hm²时，棉花颗粒剂穴施+绿豆诱集带颗粒剂穴施、灌根和颗粒剂穴施3种处理，对棉田绿盲蝽种群数量控制作用较好，自棉花苗期至8月中旬花铃期百株绿盲蝽数量分别为12、15、17、8、19头，均低于为害经济阈值，控制有效期接近110 d；在吡虫啉有效成分用量为900 g/hm²时的棉花颗粒剂穴施、灌根处理以及吡虫啉有效成分用量为675 g/hm²的棉花种子包衣+绿豆诱集带种子包衣处理，对棉田绿盲蝽种群数量控制作用次之，控制期在100 d左右。单一棉花种子包衣处理控制效果低于上述处理，持效接近90 d。各处理对棉叶受害指数减退率的影响与其对绿盲蝽种群数量的控制结果基本一致，表明棉田吡虫啉颗粒剂穴施及液体制剂灌根施药是控制绿盲蝽为害的有效施药手段。

Effects of imidacloprid on population dynamics of Apolygus lucorum under different application modes

This study explored and compared the effects of different application methods of imidacloprid, including seed coating, spot application of granules, root pouring on cotton, and planting mungbean as trapping bands, on population dynamics of Apolygus lucorum Meyer-Dür in 2011-2012. The results showed that under the amount of 1 500 g active ingredient/hm² of imidacloprid, the treatments of cotton and trapping crop with spot application of granules, cotton treated with spot application of granules, and cotton treated with root pouring achieved the best efficacy, with a long persistent period of 110 days from cotton seedling to mid-August. In this period, the numbers of A.lucorum were 12, 15, 17, 8, and 19 heads per 100 plants, respectively, which were all under the economic threshold. The followed were cotton treated with spot application of granules and cotton treated with root pouring under the amount of 900 g active ingredient/hm², cotton and trapping bands treated with seed coating with the dose of 675 g/hm² of imidacloprid, and their persistent periods were up to 100 days. The efficacy of cotton treated with seed coating was the lowest, the persistent period of which was up to 90 days. The effects of different application methods on the decreasing rate of harm index on cotton were in accordance with their inhibitions on the populations of A.lucorum. So the spot application with granules and root pouring application with soluble liquids of imidacloprid are the effective ways against A.lucorum in cotton fields.