The Amblyomma maculatum Koch group of ixodid ticks consists of three species: A. maculatum, A. triste, and A. tigrinum. However, since Koch described this group in 1844, the systematics of its members has been the subject of ongoing debate. This is especially true of A. maculatum and A. triste; recent molecular analyses reveal insufficient genetic divergence to separate these as distinct species. Further confounding this issue is the discovery in 2014 of A. maculatum group ticks in southern Arizona (AZ), USA, that share morphological characteristics with both A. triste and A. maculatum. To biologically evaluate the identity of A. maculatum group ticks from southern Arizona, we analyzed the reproductive compatibility between specimens of A. maculatum group ticks collected from Georgia (GA), USA, and southern Arizona. Female ticks from both Arizona and Georgia were mated with males from both the Georgia and Arizona Amblyomma populations, creating two homologous and two heterologous F1 cohorts of ticks: GA ♀/GA ♂, AZ ♀/AZ ♂, GA ♀/AZ ♂, and AZ ♀/GA ♂. Each cohort was maintained separately into the F2 generation with F1 females mating only with F1 males from their same cohort. Survival and fecundity parameters were measured for all developmental stages. The observed survival parameters for heterologous cohorts were comparable to those of the homologous cohorts through the F1 generation. However, the F1 heterologous females produced F2 egg clutches that did not hatch, thus indicating that the Arizona and Georgia populations of A. maculatum group ticks tested here represent different biological species.

Amblyomma maculatum Koch 蜱类蜱由三个物种组成： A. maculatum 、 A. triste和A. tigrinum 。然而，自从科赫在 1844 年描述这个群体以来，其成员的系统论一直是争论的焦点。对于A. maculatum和A. triste来说尤其如此；最近的分子分析表明，遗传差异不足以将它们区分为不同的物种。更令人困惑的是，2014 年在美国亚利桑那州南部 (AZ) 发现了A. maculatum群体蜱，它们与A. triste和A. maculatum具有共同的形态特征。为了对来自亚利桑那州南部的A. maculatum组蜱的身份进行生物学评估，我们分析了从美国佐治亚州 (GA) 和亚利桑那州南部收集的A. maculatum组蜱样本之间的生殖相容性。来自亚利桑那州和乔治亚州的雌性蜱虫与来自乔治亚州和亚利桑那州Amblyomma种群的雄性蜱虫交配，产生两个同源和两个异源的 F1 蜱群：GA ♀/GA ♂、AZ ♀/AZ ♂、GA ♀/AZ ♂ 和AZ ♀/GA ♂。每个群体被单独维持到F2代，其中F1雌性仅与来自同一群体的F1雄性交配。测量所有发育阶段的存活和繁殖力参数。观察到的异源队列的生存参数与 F1 代的同源队列的生存参数相当。然而，F1 异源雌性产生的 F2 卵窝没有孵化，因此表明这里测试的亚利桑那州和佐治亚州的斑蜱组蜱代表了不同的生物物种。