Data from: Does sex-biased dispersal account for the lack of geographic and host-associated differentiation in introduced populations of an aphid parasitoid?

Host recognition and use in female parasitoids strongly relies on host fidelity, a plastic behavior which can significantly restrict the host preferences of parasitoids, thus reducing the gene flow between parasitoid populations attacking different insect hosts. However, the effect of migrant males on the genetic differentiation of populations has been frequently ignored in parasitoids, despite its known impact on gene flow between populations. Hence, we studied the extent of gene flow mediated by female and male parasitoids by assessing sibship relationships among parasitoids within and between populations, and its impact on geographic and host-associated differentiation in the aphid parasitoid Aphidius ervi. We report evidences of a high gene flow among parasitoid populations on different aphid hosts and geographic locations. The high gene flow among parasitoid populations was found to be largely male mediated, suggested by significant differences in the distribution of full-sib and paternal half-sib dyads of parasitoid populations.

雌性寄生蜂的寄主识别与利用高度依赖寄主忠实性（host fidelity）——这是一种可塑性行为，可显著限制寄生蜂的寄主选择范围，进而降低攻击不同昆虫寄主的寄生蜂种群间的基因流（gene flow）。然而，尽管迁移雄虫对种群遗传分化的影响已被证实可作用于种群间的基因流，但在寄生蜂研究中，该效应却常被忽视。为此，本研究以蚜茧蜂（Aphidius ervi）为研究对象，通过评估种群内外寄生蜂的同胞亲缘关系（sibship relationships），探究雌雄寄生蜂介导的基因流程度，及其对种群地理与寄主关联分化的影响。本研究结果表明，取食不同蚜虫寄主、分布于不同地理区域的寄生蜂种群间存在高水平基因流。进一步分析显示，该高水平基因流主要由雄虫介导，这一结论可通过寄生蜂种群的全同胞（full-sib）与父系半同胞（paternal half-sib）对偶个体（dyads）的分布差异得到佐证。