The Asian longhorned beetle (Anoplophora glabripennis [Motschulsky]) is an invasive wood-boring beetle that threatens urban trees and forests in North America and Europe. The entomopathogenic fungus Metarhizium brunneum Petch strain F52 can infect and kill A. glabripennis adults. Products containing this fungus were available for commercial use in the United States but not registered for Asian longhorned beetle. This study tested different formulations and application rates of M. brunneum F52 microsclerotial granules for their potential development for management of A. glabripennis adults. Three application rates of M. brunneum microsclerotial granules relative to a 1× formulation from previous experiments (0.03 g/cm2; 2× = 0.06 g/cm2 and 3× = 0.09 g/cm2) were exposed on tree trunks for 4-wk periods during May-September. Increased application rates had better retention (% of initial g applied) than the 1× rate, rather than greater weathering loss. Microsclerotia at the 2× application produced 5.05 × 106 conidia/cm2, which was 18 times more conidia than the 1× application. Since A. glabripennis is under active eradication, bioassays with adult beetles were carried out in a quarantine laboratory, using the formulation samples from field exposures. The 2× application resulted in faster beetle mortality. The 3× and 2× rates were not significantly different in retention of the formulation, conidial production, or mortality, but 2× produced the most conidia per gram applied (3.92 × 109 conidia/g). An augmented formulation containing 70% M. brunneum by weight, rather than 50%, produced significantly more conidia and faster beetle mortality than the 50% formulation.

中文翻译：

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优化绿僵菌（Hypocreales：Clavicipitaceae）微菌核感染亚洲长角甲虫（鞘翅目：天牛科）的施用率

亚洲长角甲虫 (Anoplophora glabripennis [Motschulsky]) 是一种入侵的蛀木甲虫，威胁北美和欧洲的城市树木和森林。昆虫病原真菌绿僵菌 Petch 菌株 F52 可以感染和杀死光果松果蝇成虫。含有这种真菌的产品在美国可用于商业用途，但未针对亚洲长角甲虫进行注册。本研究测试了 M. brunneum F52 微巩膜颗粒的不同配方和施用率，以了解它们在管理光肩天牛成虫方面的潜力。相对于先前实验的 1x 制剂（0.03 g/cm2；2x = 0.06 g/cm2 和 3x = 0.09 g/cm2），将三种施用率的 M. brunneum 微巩膜颗粒暴露在树干上 4 周时间5 月至 9 月期间。与 1 倍率相比，增加的施用率具有更好的保留率（施用初始克的百分比），而不是更大的风化损失。施用 2 倍的微菌核产生 5.05 × 106 分生孢子/cm2，是施用 1 倍的分生孢子的 18 倍。由于 A. glabripennis 正在积极根除，因此在检疫实验室使用来自田间暴露的制剂样品对成年甲虫进行了生物测定。2 倍施用导致更快的甲虫死亡率。3x 和 2x 比率在制剂保留、分生孢子产生或死亡率方面没有显着差异，但 2x 产生的每克分生孢子最多 (3.92 x 109 分生孢子/g)。与 50% 的配方相比，含有 70% 而非 50% 重量的 M. brunneum 的增强配方产生明显更多的分生孢子和更快的甲虫死亡率。