Insecticide resistance is an increasing problem in citrus production. The Asian citrus psyllid, Diaphornia citri Kuwayama, is recognized as one of the most important citrus pests worldwide and it has developed resistance in areas where insecticides have been overused. The development of insecticide resistance is often associated with fitness costs that only become apparent in the absence of selection pressure. Here, the fitness costs associated with resistance to thiamethoxam and imidacloprid were investigated in three agricultural populations of D. citri as compared with susceptible laboratory colonies. Results showed that all field populations had greater resistance than laboratory susceptible colonies. For both thiamethoxam and imidacloprid, a Candidatus Liberibacter asiaticus-positive (CLas+) colony was more susceptible than the CLas− colony. Resistance ratios ranged from 7.65–16.11 for imidacloprid and 26.79–49.09 for thiamethoxam in field populations as compared with a susceptible, CLas− laboratory strain. Among three resistant field populations, a significantly reduced net reproductive rate and finite rate of population increase were observed in a population from Lake Wales, FL as compared to both susceptible strains. The fecundity of field populations from Lake Wales, FL was statistically lower than both laboratory susceptible populations. Certain changes in morphological characteristics were observed among resistant, as compared, with susceptible strains. Our data suggest fitness disadvantages associated with insecticide resistance in D. citri are related to both development and reproduction. The lower fitness of D. citri populations that exhibit resistance to neonicotinoid insecticides should promote recovery of sensitivity when those populations are no longer exposed to thiamethoxam and/or imidacloprid in the field. The results are congruent with a strategy of insecticide rotation for resistance management.

中文翻译：

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佛罗里达州三个柑橘黄蜂（半翅目：梨科）田间种群与噻虫嗪和吡虫啉抗性相关的健康成本

杀虫剂抗性是柑橘生产中日益严重的问题。亚洲柑橘木虱，柑橘黄萎病菌Kuwayama，被公认为世界上最重要的柑橘害虫之一，它在过度使用杀虫剂的地区产生了抗药性。杀虫剂抗性的发展通常与适应性成本相关，只有在没有选择压力的情况下才会变得明显。在这里，在三个农业种群中调查了与噻虫嗪和吡虫啉抗性相关的适应度成本。D. 柑橘与易感实验室菌落相比。结果表明，所有田间种群都比实验室易感菌落具有更大的抗性。对于噻虫嗪和吡虫啉，a候选人Liberibacter asiaticus 阳性 (C拉斯+) 菌落比C拉斯-殖民地。与易感人群相比，田间人群中吡虫啉的耐药率范围为 7.65-16.11，噻虫嗪的耐药率范围为 26.79-49.09，C拉斯-实验室菌株。在三个抗性田间种群中，与两种易感菌株相比，在佛罗里达州威尔士湖的种群中观察到了显着降低的净繁殖率和有限的种群增长率。佛罗里达州威尔士湖的田间种群的繁殖力在统计学上低于两个实验室易感种群。与易感菌株相比，在抗性菌株中观察到了形态特征的某些变化。我们的数据表明，与杀虫剂抗性相关的健康劣势D. 柑橘与发育和繁殖有关。较低的适应度D. 柑橘对新烟碱类杀虫剂表现出抗药性的种群，当这些种群不再在田间暴露于噻虫嗪和/或吡虫啉时，应促进敏感性的恢复。结果与抗性管理的杀虫剂轮换策略一致。