吡虫啉悬浮种衣剂对麦无网长管蚜实验种群的影响

Impacts of seed coating with imidacloprid on laboratory populations of Metopolophium dirhodum (Walker) (Hemiptera: Aphididae)

利用吡虫啉种子包衣技术防治麦蚜是我国小麦主产区一项重要的防控措施,目前对麦蚜的防控效果评价主要集中在自然混合种群上,对室内种群尤其是麦无网长管蚜的研究报道较少。为了明确吡虫啉种衣剂对单一蚜虫种类的影响,本文利用吡虫啉悬浮种衣剂处理的小麦苗接种4种蚜虫,分别于3、6和9 d后检查死亡率。并采用生命表方法评价种衣剂处理对麦无网长管生长发育、繁殖和种群生命参数的影响。结果表明:种衣剂处理小麦苗接种的4种蚜虫,3 d后死亡率大小依次为禾谷缢管蚜>麦长管蚜>麦二叉蚜>麦无网长管蚜,6 d后禾谷缢管蚜和麦长管蚜全部死亡;9 d后麦二叉蚜全部死亡,但麦无网长管蚜死亡率仅为10.3%。生命表结果表明:麦无网长管蚜大部分个体在种衣剂处理麦苗上可以完成整个世代周期,但其生长发育延缓,存活率、寿命和繁殖力显著下降,内禀增长率(r_m)、周限增长率(λ)、净生殖率(R_0)显著降低,平均世代周期(T)显著延长。研究结果进一步证实吡虫啉包衣处理对麦长管蚜、禾谷缢管蚜、麦二叉蚜具有很好的防治效果,但对麦无网长管蚜防效较差。

Imidacloprid seed coating treatment has been suggested as an important management for wheat aphids in the major grain-producing areas in China. The effect of imidacloprid on the control of aphids was mainly evaluated in mixed natural populations, but few studies were conducted in the laboratory population, especially Metopolophium dirhodum . To determine the effect of imidacloprid seed coating on grain aphids, four aphid species were inoculated on wheat plants seed-treated with imidacloprid, and the aphids mortality was calculated after 3, 6 and 9 d , respectively. The development, reproduction and population parameters of M. dirhodum were evaluated by using life table test. The mortalities of four aphid species after 3 d were categorized in the order from high to low as follows: Rhopalosiphum padi, Sitobion miscanthi, Schizaphis graminum, M. dirhodum. R.padi and S.miscanthi died out within 6 d, and S. graminum died out within 9 d, while the mortality of M. dirhodum was only 10.3% at 9 d. Most individuals of M. dirhodum completed the entire generation cycle, but delayed developmental time, and significantly declined survival rate, lifespan and fecundity. The intrinsic rate of increase ( r ), finite rate of increase (λ) and net reproductive rate ( R 0) were also found significantly decreased, while mean generation time ( T ) was significantly prolonged. The results further confirmed that wheat seeds treated with imidacloprid were effective against R. padi, S. avenae, and S. graminum, but poor to M. dirhodum.