金龟子绿僵菌小孢变种对筛胸梳爪叩甲幼虫致病力的生物测定

Virulence of Metarhizium anisopliae var. anisopliae to the Larvae of Melanotus cribricollis(Coleoptera:Elateridae)

从筛胸梳爪叩甲Melanotus cribricollis僵死幼虫体内分离得到1株金龟子绿僵菌小孢变种Metarhizium anisopliae var.anisopliae菌株WP,首次采用拌土法对该菌寄生筛胸梳爪叩甲幼虫的致病力进行测定,并分析外界条件对绿僵菌致病力的影响。在WP菌株1×104~1×107孢子/g干土7个孢子浓度梯度下,随着浓度的提高,筛胸梳爪叩甲的校正死亡率从20%上升至100%。在15、20、25、30℃4个温度下,该菌对筛胸梳爪叩甲的致死率随着温度升高而上升。30℃时,筛胸梳爪叩甲死亡率达96.7%;当降至15℃,筛胸梳爪叩甲不会被寄生。在6%~18%土壤湿度条件下,土壤湿度的升高会提高WP菌株对筛胸梳爪叩甲的致死率,6%的土壤湿度不会导致该虫染病。

In this paper,virulence of Metarhizium anisopliae var.anisopliae to the larvae of Melanotus cribricollis（Faldermann） was measured and the influence of environmental conditions on its virulence was assayed.Results showed that the corrected mortality of the wireworm significantly increased from 20% to 100% with the increase of the conidia concentration ranged from 1×104 to 1×107 conidia/g dry soil.In four trial temperatures,15℃,20℃,25℃ and 30℃,the mortality increased with the increase of temperature and reached to 96.7% at 30℃.No wireworm mycosis was observed at 15℃.Under other three temperatures,the higher temperature was the more mycosis.The mortality raised with the increase of moisture contents in soil ranged from 6% to 18%.In soil with 6% moisture content,no wireworm was infected.We concluded that M.anisopliae var.anisopliae had the biocontrol potentiality to reduce the density of wireworm in bamboo forests.