Insect color morphs are known to vary in detoxification enzyme activity associated with susceptibility to insecticides. Diaphorina citri occurs in three distinct color morphs, and little data are available addressing this question. In this study, susceptibility to nine insecticides was compared among orange/yellow, gray/brown and blue/green morphs of adult D. citri. Imidacloprid and lambda-cyhalothrin resulted in higher mortality in the orange/yellow morph than in the blue/green morph. The orange/yellow morph was significantly more susceptible to acetamiprid, bifenthrin and chlorfenapyr than the blue/green and gray/brown morphs. For clothianidin and chlorpyriphos, the orange/yellow morph was significantly more susceptible than the gray/brown morphs. Susceptibility to dinotefuran and thiamethoxam was not significantly different between the three color morphs of D. citri. Biochemical enzyme assays revealed that the esterase, glutathione S-transferase and cytochrome P450 activities were significantly higher in the gray/brown and blue/green morphs than in the orange/yellow morph; however, the activities of three detoxification enzymes were not significantly different between gray/brown and blue/green morphs. We analyzed the relative expression among the color morphs of six detoxification genes involved in insecticide resistance. GSTS1 and EST-6 were expressed at significantly higher levels in the blue/green morph than in the orange/yellow and gray/brown morphs. The expression levels of CYP4g15, CYP303A1, CYP4C62 and CYP6BD5 were significantly greater in the gray/brown and blue/green morphs than in the orange/yellow morph. These results suggest that insecticide susceptibility in D. citri is associated with color morphs. Detoxification enzyme activity and the relative expression of six detoxification genes may partially explain these differences. These results may facilitate further work to develop a management strategy for control of D. citri.

中文翻译：

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亚洲柑橘木虱不同颜色变体对杀虫剂敏感性的差异

已知昆虫颜色变体在与对杀虫剂的敏感性相关的解毒酶活性方面有所不同。Diaphorina citri 出现在三种不同的颜色变体中，几乎没有可用的数据来解决这个问题。在这项研究中，比较了成年柑橘果蝇的橙色/黄色、灰色/棕色和蓝色/绿色变体对 9 种杀虫剂的敏感性。吡虫啉和 λ-三氯氟氰菊酯导致橙色/黄色变体的死亡率高于蓝色/绿色变体。与蓝色/绿色和灰色/棕色变体相比，橙色/黄色变体对啶虫脒、联苯菊酯和氯芬吡酯的敏感性显着更高。对于噻虫胺和毒死蜱，橙色/黄色变体比灰色/棕色变体明显更易感。柑橘木虱的三种颜色变体对呋虫胺和噻虫嗪的敏感性没有显着差异。生化酶分析表明，灰色/棕色和蓝色/绿色形态的酯酶、谷胱甘肽 S-转移酶和细胞色素 P450 活性显着高于橙色/黄色形态；然而，三种解毒酶的活性在灰色/棕色和蓝色/绿色变体之间没有显着差异。我们分析了与杀虫剂抗性有关的六个解毒基因的颜色形态之间的相对表达。GSTS1 和 EST-6 在蓝色/绿色形态中的表达水平明显高于橙色/黄色和灰色/棕色形态。CYP4g15、CYP303A1、CYP4C62 和 CYP6BD5 在灰色/棕色和蓝色/绿色变体中显着高于在橙色/黄色变体中。这些结果表明 D. citri 对杀虫剂的敏感性与颜色变形有关。解毒酶活性和六种解毒基因的相对表达可能部分解释了这些差异。这些结果可能有助于进一步制定控制柑橘 D. citri 的管理策略。