Data from: The wheat curl mite Aceria tosichella (Acari: Eriophyoidea) is a complex of cryptic lineages with divergent host ranges: evidence from molecular and plant bioassay data

Aceria tosichella (the wheat curl mite, WCM) is a global pest of wheat and other cereals, causing losses by direct damage, as well as the transmission of plant viruses. The mite is considered to have an unusually wide host range for an eriophyoid species. The present study tested the commonly held assumption that WCM is a single, highly polyphagous species by assessing the host range of genetically distinct lineages of WCM occurring in Poland on different host plants. Genotyping was performed by analyzing nucleotide sequence data from fragments of the mitochondrial cytochrome c oxidase subunit I (COI) and the nuclear D2 region of 28S rDNA. Mean between-lineage distance estimated using COI data was found to be one order of magnitude greater than the within-clade lineage and, in some cases, comparable to distances between WCM lineages and a congeneric outgroup species. Host acceptance was tested by quantifying population growth for different WCM mitochondrial (mt)DNA lineages when transferred from source host plants to test plants. These experiments revealed significant differences in host colonization ability between mtDNA lineages, ranging from highly polyphagous to more host-specific. The present study reveals that WCM is composed of several discrete genetic lineages with divergent host-acceptance and specificity traits. Genetic variation for host acceptance within A. tosichella s.l. may act as a reproductive barrier between these lineages, most of which had narrow host ranges. Two lineages appear to have high pest potential on cereals, whereas several others appear to specialize on wild grass species. We conclude that WCM is not a homogeneous species comprising polyphagous panmictic populations rather it is a complex of genetically distinct lineages with variable host ranges and therefore variable pest potential.

小麦卷叶螨（Aceria tosichella，简称WCM）是危害小麦及其他谷类作物的全球性害虫，既可通过直接取食造成产量损失，也可传播植物病毒。作为瘿螨类物种，该螨被认为拥有异常宽泛的寄主范围。本研究针对学界普遍认为“WCM是单一且高度广食性的物种”这一假设展开验证，通过评估波兰境内不同寄主植物上的WCM遗传分化谱系的寄主范围，完成相关检验。本研究通过分析线粒体细胞色素c氧化酶亚基I（cytochrome c oxidase subunit I，COI）片段与核28S核糖体DNA（28S rDNA）D2区域的核苷酸序列数据完成基因分型。基于COI数据估算的谱系间平均遗传距离，较支系内谱系的平均遗传距离高出一个数量级；在部分案例中，该数值可与WCM谱系与其同属外类群物种间的遗传距离相当。研究通过量化不同WCM线粒体DNA（mtDNA）谱系从原寄主植物转接至试验寄主后的种群增长情况，检验其寄主接受性。试验结果显示，不同mtDNA谱系间的寄主定殖能力存在显著差异，其寄主范围从高度广食性到高度专化性不等。本研究表明，WCM并非单一均一物种，而是由多个独立的遗传谱系组成，这些谱系的寄主接受性与专化性特征存在显著分化。广义小麦卷叶螨（A. tosichella s.l.）内部的寄主接受性遗传变异，可能成为这些谱系间的生殖隔离屏障，其中多数谱系的寄主范围较为狭窄。有两个谱系在谷类作物上表现出极高的害虫危害潜力，而其余多个谱系则专性寄生于野生禾本科植物。综上，本研究得出结论：WCM并非由广食性随机交配种群构成的均一物种，而是由多个遗传分化的谱系组成的复合体；这些谱系的寄主范围各不相同，因此其害虫危害潜力也存在差异。