WANG Dingfeng, LI Jianlong, LI Huiling, LI Liangde, WANG Qingsen, WU Guangyuan
Through morphological characters and rDNA-ITS identification, a Myllocerinus aurolineatus-Beauveria strain that was isolated from tea plantation in Yingde Guangdong Province was identified to be Beauveria bassiana, and named as Bb1-1. In order to confirm the biocontrol potential of Bb1-1, two highly virulent B. bassiana strain towards M. aurolineatus weevil used as the reference, the strain growth rate, sporulation, spore germination rate, thermotolerance and UV resistance of Bb1-1, and the virulence of Bb1-1 to M. aurolineatus weevil under 25℃, 29℃ and 32℃ were tested. The results showed that there were no significant difference on the strain growth rate, spore germination rate, and UV resistance among three strains; the sporulation decreased in this order: XJBb3005> Bb1-1> XJBb3008; however, Bb1-1 showed the best thermotolerance. At 25℃, the cumulative corrective mortality of three strains were all beyond 93.94%, and there were no significance among them. However, the virulence of Bb1-1 to M. aurolineatus weevil was higher than that of the two reference strains under high temperature. At 29℃, the cumulative corrective mortality was 90.91% (7 d), LT50 value was 3.83d. At 32℃, the cumulative corrective mortality was 80% (7 d), LT50 value was 5.28 d. In consideration of Bb1-1’s good thermotolerance and the highly virulent to M. aurolineatus weevil under high temperature, it’ll play a very important role in biocontrol of M. aurolineatus weevil.