Xylosandrus germanus (Blandford) is an invasive species of ambrosia beetle known to attack apple trees in North America. Xylosandrus germanus are attracted to ethanol produced by stressed and injured trees and can be a serious problem when grafting a new cultivar onto established fruit trees (topworking). The objective of this study was to evaluate the efficacy of 2 insecticides (emamectin benzoate and azadirachtin) and injection timing (fall and spring) on their ability to control X. germanus colonization in apple trees with simulated topworking. Our study shows evidence that both emamectin benzoate and azadirachtin injections can reduce X. germanus infestations; however, our results were inconsistent. The timing of injections influenced X. germanus, with spring injected azadirachtin being more effective than fall injections. Residue analyses of emamectin benzoate and azadirachtin showed the presence of residues in woody tissue comparable to those found in leaves.

中文翻译：

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树干注射以控制顶部加工的苹果树中的德国木山梨（鞘翅目：象甲科）

德国木山梨 (Blandford) 是豚草甲虫的一种入侵物种，已知会攻击北美的苹果树。德国木山梨会被受压和受伤的树木产生的乙醇所吸引，当将新品种嫁接到已建成的果树上时（顶部作业），这可能会成为一个严重的问题。本研究的目的是评估 2 种杀虫剂（甲维菌素苯甲酸盐和印楝素）的功效和注射时机（秋季和春季）对通过模拟顶部作业控制苹果树上德国小蠹定殖的能力的影响。我们的研究表明，有证据表明，甲维盐苯甲酸盐和印楝素注射液都可以减少德国小孢子虫感染；然而，我们的结果并不一致。注射时间会影响德国 X. germanus，春季注射印楝素比秋季注射更有效。甲维盐苯甲酸盐和印楝素的残留分析表明，木质组织中的残留量与叶子中的残留量相当。