Data from: The effect of parasitism and interpopulation hybridization on Aedes albopictus (Diptera: Culicidae) fitness

Recent research in mosquito population genetics suggests that interpopulation hybridization has likely contributed to the rapid spread of the container-breeding mosquitoes. Here, I used laboratory experiments to investigate whether interpopulation Aedes (Stegomyia) albopictus (Skuse) F1 and F2 hybrids exhibit higher fitness than parental populations, and whether hybrid mosquito performance is related to infection by the coevolved protozoan parasite Ascogregarina taiwanensis (Lien and Levine). Overall, there were significant differences in development time, wing length, and survival between the two parental mosquito populations, but no difference in per capita growth rate r. Hybrid mosquitoes were generally intermediate in phenotype to the parentals, except that F2 females were significantly larger than the midparent average. In addition, As. taiwanensis parasites produced fewest oocysts when they were reared in hosts of hybrid origin. These data suggest that hybridization between previously isolated mosquito populations can result in slight increases in potential mosquito reproductive success, via increased hybrid body size, and via the temporary escape from coevolved parasites. These findings are significant because studies have shown that even slight hybrid vigor can have positive fitness consequences for population persistence. Although this was a laboratory experiment extending only to the F2 generation, many other invasive insects also carry coevolved parasites, and thus the patterns seen in this mosquito system may be broadly relevant.近年来蚊虫群体遗传学领域的研究表明，种群间杂交可能推动了容器孳生蚊虫的快速扩散。本研究通过实验室实验，探究了白纹伊蚊（Aedes (Stegomyia) albopictus）（Skuse）的F1与F2代杂交个体是否较亲本种群具备更高的适合度，以及杂交蚊虫的表现是否与共进化原生动物寄生虫台湾艾格虫（Ascogregarina taiwanensis）（Lien and Levine）的感染状态相关。总体而言，两个亲本蚊虫种群在发育时长、翅长与存活率上存在显著差异，但单位个体增长率r并无显著区别。杂交蚊虫的表型大多介于亲本之间，仅F2代雌蚊的体型显著大于双亲平均水平。此外，当台湾艾格虫寄生在杂交起源的宿主体内时，其卵囊产量最低。上述数据表明，此前彼此隔离的蚊虫种群间的杂交，可通过提升杂交个体体型、暂时摆脱共进化寄生虫的双重途径，小幅提升蚊虫的潜在繁殖成功率。该发现具有重要研究价值，因为已有研究证实，即便微弱的杂种优势也能对种群存续产生积极的适合度影响。尽管本实验仅在实验室条件下开展且仅延伸至F2代，但诸多其他入侵昆虫也携带共进化寄生虫，因此本蚊虫研究体系中观察到的模式可能具备广泛的普适性参考意义。