昆虫病原真菌与硅藻土混用对四纹豆象的毒力效果(英文)

Efficacy of entomopathogenic fungi in combination with diatomaceous earth against Callosobruchus maculatus (Coleoptera: Bruchidae)

在室内条件下检测了白僵菌Beauveria bassiana（Balsamo）Vuillemin菌株IRAN-187C和金龟子绿僵菌Metarhizium anisopliae （Metschnikow）Sorokin菌株 A-396 分别与硅藻土（DE）制剂（InsectoSec）~混用对四纹豆象Callosobruchus maculatus成虫的毒力效果。结果表明：硅藻土与致死剂量和亚致死剂量的真菌分离物混用导致了四纹豆象成虫的高死亡率,且这些处理均缩短了真菌的致死中时（LT50）。LC50的白僵菌B.bassiana菌株IRAN-187C和LC50的DE混用对四纹豆象的 LT50（122.2h）最低,在95%置信限上与LC50的金龟子绿僵菌M.anisopliae菌株A-396与LC50的DE混用得到的LT50（128.2h）相当,说明两种真菌分离物与DE混用对四纹豆象成虫都具有较好的毒力效果。用四纹豆象成虫检测3个温度（22,27和30℃）和2个相对湿度（40%和55%）组合对DE活性的影响,结果显示30℃和40%相对湿度条件下得到的LT50（110.11h）最低,说明高温低湿条件下DE活性较高。

Experiments were conducted to enhance the virulence of two isolates of entomopathogenic fungi, IRAN-187C of Beauveria bassiana （Balsamo） Vuillemin, and A-396 isolate of Metarhizium anisopliae （Metschnikow） Sorokin, by combination with InsectoSec formulation of diatomaceous earth （DE） against the adults of Callosobruchus maculatus F. under laboratory conditions. The results demonstrated that the combinations between diatomaceous earth and the fungal isolates at lethal and sub-lethal doses achieved high mortality rates in the adult populations ; moreover, the treatments improved LT50 values of the fungi. The lowest value of LT50（122. 2 h） was achieved by LC50（B. bassiana, IRAN-187C） ＋ LCs0（DE） treatment which was on par with that of LC50（M. anisopliae, A-396） ＋ LC50（DE） combination （128.2 h） based on their 95% fiducial limit values, resulting in better efficacy of each fungal isolate in combination with diatomaceous earth against C. maculatus adults. Also, effects of the three temperatures （22, 27, and 30℃ ） and two relative humidity levels （40% and 55% ） on the activity of diatomaceous earth when applied against C. maculatus adults showed that the least value of LTs0 （110.11 h） was attained in 30℃ and RH of 40% , suggesting high activity of diatomaceous earth in high temperatures and low humidity conditions.