不同浓度吡虫啉包衣处理在油菜上的应用Ⅰ.对蚜虫种群发展的影响

Application of imidacloprid coating on the seeds of oilseed rape Ⅰ. Effects on the aphid development

在田间条件下研究了吡虫啉(高巧,60%悬浮剂)包衣处理对油菜蚜虫发生的影响。播种前对油菜种子进行不同浓度(药种比分别为1∶5、1∶25、1∶125)的药剂包衣处理,结果表明,经处理后的油菜在苗期和花期后的蚜虫发生量均显著低于对照,并且花期后不同浓度药剂处理间存在一定差异,药种比最低的处理上发生少量蚜虫而药种比最高的处理上蚜虫未发生;药剂包衣处理后的油菜上有翅蚜的比例发生显著变化,最低药种比处理中有翅蚜比例维持在6%~10%,中浓度药种比处理中在油菜苗期不发生有翅蚜,但在花期其有翅蚜比例超过20%,至结角期有翅蚜比例仍达到15%左右;中浓度处理田块中有翅蚜可在未经过药剂处理的油菜上快速繁殖并建立种群,个体发生量与对照差异虽不显著(P=0.6),但在数值上略高。以上结果说明,不同浓度吡虫啉包衣处理可有效防控蚜虫对油菜的为害,但中浓度处理可导致有翅蚜大量发生及蚜群后代繁殖力提升。

Effects of imidacloprid（Gaucho） coating on aphids in fields of oilseed rape were studied. Seeds were treated by Gaucho in different ratios of 1∶ 5,1∶ 25 and 1∶ 125（weight of chemical versus seed）. The results showed that 1） aphids occurred on the seedlings in the treatments were significantly less than the control,and so were in the flowering stages when no aphid was found in the highest treatment and a few aphids in the lowest treatment; 2） ratios of alate aphid between the treatments were significantly different. 6% ~ 10% alate aphids appeared in the lowest treatment,while zero in the medium treatment,in the seedlings,over 20% in the flowers and 15% in the fruits; 3）aphids collected in fields of medium treatment could establish a quick-developing population on untreated plants,and counts of individuals were slightly higher than the control,but showing no statistical difference（P = 0. 6）. The a-bove results suggested that coating by imidacloprid could effectively control the aphids occurred on the oilseed rape,but a medium coating concentration could result in flourishing of alate aphids and increased reproductive ability.