Data from: Survival relative to new and ancestral host plants, phytoplasma infection and genetic constitution in host races of a polyphagous insect disease vector

Dissemination of vectorborne diseases depends strongly on the vector's host range and the pathogen's reservoir range. Because vectors interact with pathogens, the direction and strength of a vector's host shift is vital for understanding epidemiology and is embedded in the framework of ecological specialization. This study investigates survival in host-race evolution of a polyphagous insect disease vector, Hyalesthes obsoletus, whether survival is related to the direction of the host shift (from field bindweed to stinging nettle), the interaction with plant-specific strains of obligate vectored pathogens/symbionts (stolbur phytoplasma), and whether survival is related to genetic differentiation between the host races. We used a twice repeated, identical nested experimental design to study survival of the vector on alternative hosts and relative to infection status. Survival was tested with Kaplan–Meier analyses, while genetic differentiation between vector populations was quantified with microsatellite allele frequencies. We found significant direct effects of host plant (reduced survival on wrong hosts) and sex (males survive longer than females) in both host races and relative effects of host (nettle animals more affected than bindweed animals) and sex (males more affected than females). Survival of bindweed animals was significantly higher on symptomatic than nonsymptomatic field bindweed, but in the second experiment only. Infection potentially had a positive effect on survival in nettle animals but due to low infection rates the results remain suggestive. Genetic differentiation was not related to survival. Greater negative plant-transfer effect but no negative effect of stolbur in the derived host race suggests preadaptation to the new pathogen/symbiont strain before strong diversifying selection during the specialization process. Physiological maladaptation or failure to accept the ancestral plant will have similar consequences, namely positive assortative mating within host races and a reduction in the likelihood of oviposition on the alternative plant and thus the acquisition of alternative stolbur strains.虫媒传染病（vectorborne diseases）的传播很大程度上取决于媒介昆虫（vector）的宿主范围与病原体的储存宿主范围。鉴于媒介昆虫与病原体存在相互作用，媒介昆虫的宿主转移方向与强度对流行病学研究至关重要，且该过程隶属于生态特化的研究框架。本研究针对多食性昆虫病媒媒介凹缘菱纹叶蝉（Hyalesthes obsoletus）的宿主宗演化存活情况展开探究，具体考察三项内容：其一，存活是否与宿主转移方向（从田旋花至荨麻）相关；其二，存活是否与专性虫媒病原体/共生体——斯多尔布尔植原体（stolbur phytoplasma）的植物特异性菌株间存在互作关联；其三，存活是否与宿主宗间的遗传分化相关。我们采用两次重复的相同嵌套实验设计，分析病媒媒介在替代宿主上的存活情况，并结合感染状态开展对照研究。存活情况通过卡普兰-迈耶分析法（Kaplan–Meier analyses）进行检验，媒介种群间的遗传分化则通过微卫星等位基因频率进行量化。研究结果显示：两种宿主宗均存在宿主植物（在非适配宿主上存活率显著降低）与性别（雄性存活时长显著长于雌性）的显著直接效应；同时宿主与性别存在相对效应：荨麻宿主宗受宿主类型的影响程度高于田旋花宿主宗，雄性受性别的影响程度高于雌性。田旋花宿主宗在带症田旋花上的存活率显著高于无症状田旋花，但该结果仅在第二次实验中成立。荨麻宿主宗的感染状态可能对存活存在正向影响，但由于感染率较低，该结果仅具参考意义。遗传分化与存活率并无显著关联。在衍生宿主宗中，宿主转移带来的负向效应更为显著，但斯多尔布尔植原体并未表现出负向效应，这表明在特化过程中经历强烈分裂选择前，该宿主宗已对新型病原体/共生体菌株产生预适应。生理适应不良或无法接纳原始宿主将带来相似后果：即宿主宗内出现正向选型交配，且在替代植物上产卵的概率降低，进而减少了替代斯多尔布尔菌株的获取概率。