三株丝孢虫生真菌对松墨天牛幼虫的感染效应

 生物测定了球孢白僵菌（Beauveria bassiana）Bb050715,Bb060721菌株和粉拟青霉（Paecilomyces farinasus）Pf0607菌株对松墨天牛（Monochamus alternatus Hope）的感染效应。结果表明,球孢白僵菌及粉拟青霉对松墨天牛幼虫的毒力有一定的差异,3株丝孢真菌侵染三龄幼虫后,均造成虫体血淋巴中蛋白质含量降低,且球孢白僵菌侵染后血淋巴中总蛋白含量明显低于经粉拟青霉接种处理感染后的虫体。供试3菌株中,球孢白僵菌菌株处理后天牛累积死亡率明显高于粉拟青霉菌株,对天牛幼虫感染的剂量效应参数分别为0.45,0.45和0.39,对松墨天牛三龄幼虫的毒力回归方程分别为Y=13.537X-4.603²(R²=0.97),Y=15.361X+0.444 4(R²=0.97)和Y=9.138X-3.100 1(R²=0.99)。在1.36×10⁴～1.36×10⁹孢子/mL下处理后第4d才出现死亡,Bb050715,Bb060721和粉拟青霉3菌株接种处理后第4～8d的累积死亡率分别为13.3%～80.0%,13.3%～86.7%,6.7%～53.3%,LT₅₀依次为5.1,5.1和7.7d,第5 d的LC₅₀分别为7.23×10⁸孢子/mL,1.53×10⁸孢子/mL,7.27×10⁹孢子/mL。

Infection Effect of Three Isolates of Entomopathogenic Fungi against the Larvae of the Monochamus alternatus Hope

The infection effect of isolates of Bb050715 and Bb060721 strains of Beauveria bassiana, and the strain of Pf0607 of Paecilomyces farinasus against the larvae of pine sawyers, Monochamus alternatus Hope were tested in laboratory. The result showed that the virulence was different between B.bassiana and P.farinasus, and the protein content in haemolymph of the 3rd instar larvae of the M.alternatus infected by the isolates of B.bassiana decreased obviously and was less than that of the larvae infect by P.farinasus. The cumulative mortality of the 3rd instar larvae of the M.alternatus infected by the isolates of B.bassiana were obviously higher than that of the larvae infect by P.farinasus. The dose-effect parameters of the tested isolates were 0.45,0.45 and 0.39, respectively, on larvae of the M.alternatus. The virulence equation was Y=13.537X－4.603 2 (R²=0.97), Y=15.361X+0.444 4 (R₂=0.97) and Y=9.138 X-3.100 1 (R²=0.99), respectively. The LT₅₀was 5.1, 5.1 and 7.7 days, separatelyIts LC₅₀ on the larvae against sawyer was 1.38×10 spores /mL. The cumulative mortalities were 13.3%～80%, 13.3%～86.7%, 6.7%～53.3%, respectively, after the inoculation of the dosage of 1.36×10⁴～1.36×10⁹ spores/mL, and the first mortality was in the 4th day after treatment. The LC₅₀ in the day 5 was 7.23×10⁸ spores/mL, 1.53×10⁸ spores/mL, 7.27×10⁹ spores/mL.