Interactive effect of low concentration buprofezin and Metarhizium anisopliae var. acridum on the mortalities of Nilaparvata lugens (Homoptera: Delphacidae) nymphs and adults in laboratory bioassays
摘 要 ：在实验室中测定了低浓度噻嗪酮与黄绿绿僵菌Metarhizium anisopliae var. acridum对褐飞虱Nilaparvata lugens不同龄期若虫和成虫的协同致死作用。结果表明,低浓度噻嗪酮与黄绿绿僵菌混合施用时对褐飞虱表现明显的协同作用。与单独施用噻嗪酮相比,混合施用时对低龄若虫的LT50缩短了约22 天;对高龄若虫的LT50缩短了约57天;单独施用时对成虫几乎没有作用,而混合施用时的LT50为3.77 天。与单独施用黄绿绿僵菌相比,混合施用时对低龄若虫、高龄若虫、成虫的LT50也都缩短了1~2 天。混合施用时对不同发育阶段的褐飞虱的毒力顺序为成虫>高龄若虫>低龄若虫。
Abstract:Bioassay was conducted to evaluate the interactive effect of low concentration buprofezin with Metarhizium anisopliae var. acridum on the mortality of brown planthopper (BPH), Nilaparvata lugens, nymphs and adults. Three treatments were included in the experiments: 2.5 μg/mL buprofezin, 107 conidia/mL, and 2.5 μg/ mL buprofezin +107 conidia/mL. Three developmental stages of BPH, young nymphs (1-2 instars), old nymphs (3-5 instars) and adults, were tested in each treatment. The results showed that a significantly increased efficacy of M. anisopliae var. acridum against BPH when combined with low concentration buprofezin was achieved. The LT50 estimates decreased 22 d to young nymphs, 57 d to old nymphs and greatly to adults compared to those in the treatments of buprofezin alone. The LT50 estimates decreased 1-2 d to all the nymphs and adults compared to those in the treatments with M. anisopliae var. acridum alone. The virulence sequence of 2.5 μg/mL buprofezin +107 conidia/mL M. anisopliae var. acridum against N. lugens was in the order of adults > old nymphs > young nymphs.