Abstract The duration of the evolutionary association between a pathogen and vector can be inferred based on the strength of their mutualistic interactions. A well-adapted pathogen is likely to confer some benefit or, at a minimum, exhibit low pathogenicity toward its host vector. Coevolution of the two toward a mutually beneficial association appears to have occurred between the citrus greening disease pathogen, Candidatus Liberibacter asiaticus (Las), and its insect vector, the Asian citrus psyllid, Diaphorina citri (Kuwayama). To better understand the dynamics facilitating transmission, we evaluated the effects of Las infection on the fitness of its vector. Diaphorina citri harboring Las were more fecund than their uninfected counterparts; however, their nymphal development rate and adult survival were comparatively reduced. The finite rate of population increase and net reproductive rate were both greater among Las-infected D. citri as compared with uninfected counterparts, indicating that overall population fitness of infected psyllids was improved given the greater number of offspring produced. Previous reports of transovarial transmission, in conjunction with increased fecundity and population growth rates of Las-positive D. citri found in the current investigation, suggest a long evolutionary relationship between pathogen and vector. The survival of Las-infected adult D. citri was lower compared with uninfected D. citri, which suggests that there may be a fitness trade-off in response to Las infection. A beneficial effect of a plant pathogen on vector fitness may indicate that the pathogen developed a relationship with the insect before secondarily moving to plants.

中文翻译：

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更好的结合：与'CandidatusLiberibacter Asiaticus'的关联增加了其昆虫载体Diphorina citri（半翅目：Liviidae）的繁殖适应性

摘要 病原体和载体之间进化关联的持续时间可以根据它们互惠相互作用的强度来推断。适应良好的病原体可能会带来一些好处，或者至少对宿主载体表现出低致病性。柑橘绿化病病原体 Candidatus Liberibacter asiaticus (Las) 与其昆虫载体亚洲柑橘木虱 Diaphorina citri (Kuwayama) 之间似乎发生了两者朝着互利关联的共同进化。为了更好地了解促进传播的动力学，我们评估了 Las 感染对其载体适应性的影响。带有 Las 的柑橘木虱比未受感染的同类繁殖力更强；然而，它们的若虫发育率和成虫存活率相对降低。与未受感染的对应物相比，受 Las 感染的柑橘木虱的有限种群增长率和净繁殖率均更高，这表明受感染木虱的总体种群适应性因产生更多后代而得到改善。先前关于跨卵巢传播的报告，连同在当前调查中发现的 Las 阳性柑橘叶霉的繁殖力和种群增长率增加，表明病原体和载体之间存在长期的进化关系。与未感染的柑橘果蝇相比，受 Las 感染的成年柑橘果蝇的存活率较低，这表明可能存在对 Las 感染的适应性权衡。