金龟子绿僵菌KMa0107对马铃薯块茎蛾的侵染致病效应

采用浸渍法在室内生物测定了金龟子绿僵菌KMa0107菌株对马铃薯块茎蛾2~4龄幼虫的毒力，并运用时间-剂量-死亡率模型分析了其致死剂量和致死时间等致病效应。结果表明：绿僵菌KMa0107菌株对马铃薯块茎蛾幼虫具有良好的侵染致病作用，接种处理后各龄幼虫的感病死亡率随接种密度的升高而增加，当用1.15108 mL-1密度接种后第7天时，马铃薯块茎蛾2、3和4龄幼虫的累计死亡率分别为96.67%、90.00%和83.33%，感病顺序表现为2龄 3龄 4龄。用金龟子绿僵菌KMa0107菌株接种马铃薯块茎蛾2、3、4龄幼虫后第3~7天时，LC50估计值分别为1.85106~1.10105、6.59107~2.41105和3.69107~5.85105 mL-1，LC90估计值分别为2.43108~1.44107、7.97108~2.93107和4.34109~6.89107 mL-1。用1.15105~1.15108 mL-1孢子悬浮液接种马铃薯块茎蛾2、3、4龄幼虫后，LT50值分别为5.91~1.33、4.18~1.67和5.14~2.42 d。该研究表明：金龟子绿僵菌KMa0107菌株对马铃薯块茎蛾具有良好的侵染致病效应，在马铃薯块茎蛾生防制剂开发中具有良好潜力。

The Infection Effect of Metarhizium anisopliae KMa0107 against the Larvae of Potato Tuber Moth,Phthorimaea operculella(Zeller)

The infection effect of the strain KMa0107 of Metarhizium anisopliae against the potato tuber moth larvae was tested in the laboratory by immersing larvae of different instars into conidia concentrations of the fungus. The mortality of the potato tuber moth caused by infection of M.anisopliae increased with the increase of the concentration of conidial suspension and the time after treatment. The highest concentration (1.15108 mL-1) treatment the mortality was 96.67%, 90.00% and 83.33% for 2nd,3rd, and 4th instar larvae on 7th day, respectively. The virulence of M. anisopliae to the potato tuber moth differed with larval stages. The susceptibility of the potato tuber moth larvae to M.anisopliae decreased in the sequence of 2nd instar, 3rd instar, and 4th instar. The estimated LC50 values of the 2nd instar on 7th day after treatment, the 3rd instar on the 5th day after treatment and the 4th instar on day 4th after treatment was 1.85106~1.10105,6.59107~2.41105 and 3.69107~5.85105 mL-1, respectively,while LC90 of 2nd,3rd, 4th instar larvae was 2.43108~1.44107,7.97108~2.93107, and 4.34109~6.89107 mL-1, respectively. The median letha ltime of M. anisopliae to the potato tuber moth larvae differed with different concentrations, LT50 values of all tested instars were shortened with the increase of concentration, the short LT50 for the 2nd instar, add the longest LT50 was for the 4th instars. LT50 value was 5.91~1.33, 4.18~1.67 and 5.14~2.42 d for the 2nd, 3rd and 4th instar larvae under the inoculation of 1.15105~1.15108mL-1 suspensions. The results suggested the strain KMa0107 of M. anisopliae showed a good infect effect against the larvae of P. operculella and with a well development potentiality for the of biological control agents for the biological control on P. operculella.