不同来源绿僵菌菌株对椰心叶甲的毒力测定

 利用绿僵菌菌株SY-2，WC-1，SX-2，HK-5 QH-4，HY-4，YP-6，SS-2对椰心叶甲幼虫和成虫的毒力进行了测定, 采用时间-剂量-死亡率模型分析了绿僵菌对椰心叶甲的毒力。结果表明，其致病力强弱与菌株种类和接种剂量有密切关系，在1.0×106-1.0×108个/mL孢子悬浮液接种处理后第10天，椰心叶甲3龄幼虫累积死亡率均为74%～92%，接种SY-2菌株的孢子浓度在1.0×108个/mL情况时，对3龄幼虫的死亡率为96.70%，LT50为3.8d，与HY-4，YP-6,和SS-2，(死亡率88.36%)相比具有显著差异（P<0.05）；在1.0×106~10×108个/mL孢子悬浮液接种处理后第10天，椰心叶甲成虫累积死亡率53%～76%，接种SY 2菌株的孢子浓度在1.0×108个/mL情况时，对成虫的死亡率为85.03%，LT50为5.4d，与SS-2（死亡率为70%）相比，SY-2，WC-1和SX-2具有显著差异（P<0.05）；另外，观察发现，SY-2菌株具有很强的2次侵染能力。

The Virulence Test of Different Strains of Metarhizium anisopliae against Brontispa longissima

The pathogenicity of eight Metarhizium anisopliae strains against larvae and adult of Brontispa longissima (Gestro) were bioassayed in laboratory by spraying. A time dose mortality model was applied to analysis of the variation of mortality rates. The model showed that close relationship was found between the virulence and the strains and their inoculation rate. At a concentration of 1.0×106-1.0×108 conidia/mL, the mortality rates of M. anisopliae strains SY-2,WC-1,SX-2,HK-5,QH-4,HY-4,YP-6 and SS-2 against the larvae of B. longissima were 74%～92%. The mortality and LT50 of the 3rd larvae of B. longissima inoculated with SY-2 strain at 1.0×108 spores/mL was 96.7% and 3.8d with significant effect (P＜0.05) different from that treated HY 4,YP 6 and SS 2 (mortality rate 88.36%）. At a concentration of 1.0×106~1.0×108 conidia/ mL, the mortality rates of M. anisopliae strains SY-2, WC-1, SX-2, HK-5, QH-4, HY-4, YP-6 and SS-2 against the adult of B. longissima were 53%～76%. The mortality and LT50 of  the adult of B.longissima inoculated with SY 2 strain at 10×108 spores/mL was 85.03% and 54d with significant effect (P＜0.05) SY-2,WC-1 and SX-2 significantly different from that treated SS-2. The SY-2 was found to have very strong second infection ability