Abstract Adult ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) bore into ornamental nursery trees resulting in trunk vascular tissue damage, which can potentially kill trees. Ambrosia beetle exposure to surface-applied insecticides is minimal after internal trunk galleries are formed, so effective management requires insecticide treatments to be applied near the time of infestation or to have residual activity on the bark. Tree trunk sections (bolts) were used to determine the effect of field aging or irrigation (i.e., simulated rainfall weathering) on permethrin residual activity against ambrosia beetles. In all experiments, 30-cm-long bolts from Liriodendron tulipifera L. (Magnoliales: Magnoliaceae) were hollowed and filled with 70% ethanol at field deployment to induce ambrosia beetle attacks over a 2-wk period. To evaluate insecticide residual activity, permethrin was sprayed onto tree bolts at 0, 8, 17, or 24 d before ethanol addition, and then bolts were deployed along a wooded border in fall 2017 and spring 2018. Tree bolts with permethrin residues ≤17 d old had significantly fewer ambrosia beetle attacks than bolts with 24-d-old residues or the non-permethrin-treated control bolts. To evaluate simulated rainfall weathering, permethrin was applied to tree bolts 8 or 22 d before ethanol (spring 2018) or 10 or 24 d before ethanol (fall 2018) with half of the bolts receiving regular irrigation events. Irrigation had no significant effect on permethrin residual activity against ambrosia beetles during either test. This study determined ambrosia beetle control was affected by permethrin residue age more than simulated rainfall weathering, and a reapplication interval of ≤17 d maximized beetle control.

中文翻译：

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氯菊酯对田间老化和模拟降雨风化后豚草甲虫（鞘翅目：象甲科：小蠹亚科）攻击的残留活性


摘要 成年豚草甲虫（鞘翅目：象甲科：小蠹亚科）钻入观赏苗圃树木，导致树干维管组织损伤，可能导致树木死亡。在形成内部树干通道后，豚草甲虫接触表面施用的杀虫剂的情况很少，因此有效的管理需要在接近侵染时施用杀虫剂处理或在树皮上具有残留活性。树干截面（螺栓）用于确定田间老化或灌溉（即模拟降雨风化）对氯菊酯针对豚草甲虫的残留活性的影响。在所有实验中，在野外部署时，将来自 Liriodendron tulipifera L.（木兰目：木兰科）的 30 厘米长的螺栓挖空并填充 70% 乙醇，以在 2 周内诱导豚草甲虫攻击。为了评估杀虫剂残留活性，在添加乙醇前 0、8、17 或 24 天将氯菊酯喷洒到树栓上，然后在 2017 年秋季和 2018 年春季沿树木繁茂的边界部署栓剂。氯菊酯残留≤17 天的树栓与具有 24 天残留物的螺栓或未经氯菊酯处理的对照螺栓相比，老螺栓的豚草甲虫攻击明显减少。为了评估模拟降雨风化，在使用乙醇之前 8 或 22 天（2018 年春季）或使用乙醇之前 10 或 24 天（2018 年秋季）将氯菊酯施用到树栓上，其中一半的栓进行定期灌溉。在这两个测试中，灌溉对氯菊酯对豚草甲虫的残留活性没有显着影响。这项研究确定，与模拟降雨风化相比，豚草甲虫控制更受氯菊酯残留年龄的影响，并且≤17天的重新施用间隔可以最大限度地发挥甲虫控制作用。