Department of Entomology, Comstock Hall, Cornell University, Ithaca, NY 14853-2601, USA.
J Invertebr Pathol. 2010 Nov;105(3):305-11. doi: 10.1016/j.jip.2010.08.009. Epub 2010 Aug 31.
Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), a longhorned beetle species native to Asia, has been introduced into several North American and European cities. Currently eradication and preventive measures are limited to identifying and destroying infested trees and protecting uninfested trees with trunk or soil-injections of the systemic insecticide imidacloprid. Because entomopathogenic fungi like Metarhizium brunneum Petch have been identified as virulent against these beetles we conducted several tests to determine the compatibility of the two agents in combination. Radial hyphal growth and the sporulation capacity of M. brunneum on Sabouraud dextrose agar with yeast were not significantly affected by the presence of imidacloprid. In a 2×3 factorial experiment investigating interactions between exposure to imidacloprid and M. brunneum we observed no effect of imidacloprid alone on beetle survival when beetles were given a single dose of 10 or 100 ppm compared to control insects. We observed a significant effect of exposure to M. brunneum, and a significant interaction between imidacloprid and M. brunneum representing a synergistic effect of dual treatment. Beetles exposed to the fungus alone lived significantly longer compared to insects treated with a single dose of 100 ppm imidacloprid (9.5 vs. 6.5d). Consumption of striped maple twigs by beetles exposed to imidacloprid, across concentrations, was reduced 48% compared to control insects, where as consumption by M. brunneum-exposed beetles was reduced by 16% over the first 6-days of the test period. Beetles fed 100 ppm imidacloprid consumed 32% less over the first 3d compared to beetles not exposed to imidacloprid and thereafter consumed as much as beetles not fed 100 ppm imidacloprid. M. brunneum-exposed beetles consumed significantly less food than control insects throughout the test period, and beetles treated with imidacloprid produced significantly fewer conidia compared to beetles not treated with imidacloprid.
光肩星天牛(Anoplophora glabripennis)(鞘翅目:天牛科)原产于亚洲,已被引入北美和欧洲的多个城市。目前,根除和预防措施仅限于识别和销毁受感染的树木,并通过树干或土壤注射内吸性杀虫剂噻虫啉来保护未受感染的树木。由于白僵菌(Metarhizium brunneum Petch)等昆虫病原真菌已被鉴定为对这些甲虫具有毒性,我们进行了几项测试来确定这两种药剂联合使用的兼容性。噻虫啉的存在并未显著影响白僵菌在含酵母的萨布罗琼脂上的径向菌丝生长和孢子形成能力。在一项调查噻虫啉与白僵菌相互作用的 2×3 析因实验中,与对照昆虫相比,当甲虫单次接受 10 或 100 ppm 剂量的噻虫啉时,单独使用噻虫啉对甲虫存活没有影响。我们观察到白僵菌暴露的显著影响,以及噻虫啉和白僵菌之间的显著相互作用,代表双重处理的协同作用。单独暴露于真菌的甲虫的存活时间明显长于接受 100 ppm 噻虫啉单剂量处理的昆虫(9.5 天对 6.5 天)。暴露于噻虫啉的甲虫对条纹枫嫩枝的消耗量比对照昆虫减少了 48%,而暴露于白僵菌的甲虫在试验期的前 6 天内的消耗量减少了 16%。与未暴露于噻虫啉的甲虫相比,喂食 100 ppm 噻虫啉的甲虫在前 3 天的消耗量减少了 32%,此后的消耗量与未喂食 100 ppm 噻虫啉的甲虫相同。在整个试验期间,暴露于白僵菌的甲虫消耗的食物明显少于对照昆虫,并且用噻虫啉处理的甲虫产生的分生孢子明显少于未用噻虫啉处理的甲虫。