We investigated the colonization potential of five Metarhizium anisopliae isolates on pine tree surfaces under laboratory conditions, determined the influence of the pine bark extract on fungal growth and evaluated the insecticidal activity following colonization on the Japanese pine sawyer. Finally, the effect of colonization on adults pine sawyer was evaluated using the top three performing isolates (JEF-197, JEF-271 and JEF-279) under laboratory and field conditions. As a result, isolate JEF-197 showed the highest conidial production on the pine surfaces, and five isolates, including JEF-197, showed higher hyphal growth on autoclaved pine bark extract agar, compared to a water agar. Pine bark treated with the isolates showed 40-70 % mortality of adults pine sawyer. Under mimicked overwintering conditions, in the JEF-197 treatment group, 40 % of the inserted larvae became adults and all were dead after 59 d. In a field test, colonized isolate JEF-197 also showed 37 % insecticidal activity against emerged adults from the pine logs as overwintering sites. This work suggests that M. anisopliae isolate JEF-197 possibly colonized the pine surface and application of a conidial suspension on the pine logs as overwintering sites could be an effective strategy to control the pine sawyer.

中文翻译：

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绿僵菌在松树原木表面的定植：一种有希望的日本松木锯木的生物防治策略，Monochamus alternatus

我们在实验室条件下研究了五种绿僵菌分离株在松树表面的定殖潜力，确定了松树皮提取物对真菌生长的影响，并评估了在日本松树锯木上定殖后的杀虫活性。最后，在实验室和田间条件下，使用表现最好的三个分离株（JEF-197、JEF-271 和 JEF-279）评估定植对成年松树的影响。结果，分离株 JEF-197 在松树表面显示出最高的分生孢子产量，与水琼脂相比，包括 JEF-197 在内的五个分离株在高压灭菌的松树皮提取物琼脂上显示出更高的菌丝生长。用分离株处理的松树皮显示成年松树锯木的死亡率为 40-70%。在模拟越冬条件下，在 JEF-197 治疗组中，40%的插入幼虫成虫，59 d后全部死亡。在田间试验中，定殖分离株 JEF-197 也显示出 37% 的杀虫活性，对抗从松木原木作为越冬地的成虫。这项工作表明 M. anisopliae 分离株 JEF-197 可能定植于松树表面，在松木原木上应用分生孢子悬浮液作为越冬地点可能是控制松木锯木的有效策略。