ABSTRACT Understanding how patterns of host-seeking behaviour differ across demographic classes in Amblyomma americanum (L.), the lone star tick, is essential in evaluating species potential as a vector of pathogens. Our objective was to characterize the relative contributions of two cryptic developmental cohorts, newly moulted and overwintered adults, to the A. americanum host-seeking population. To determine cohort identity, we used haem concentration as a metric of physiological age in ticks collected from field and forest habitats. Emergence of ticks displaying uncharacteristically high haem concentrations in late spring and early summer would indicate that newly moulted adults resume questing activity in the same season of their nymphal engorgement. Overall, haem concentration decreased significantly throughout the active season of adults from March to July of 2017 in northeast Missouri. Males displayed higher average haem concentrations than females when controlled for date of capture, but habitat-mediated differences were not significant. No subset of ticks with inflated haem concentrations was collected during the time that activization of newly moulted adults was feasible, suggesting that A. americanum adults undergo post-moulting behavioural diapause under natural conditions.

中文翻译：

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使用血红素浓度作为生理年龄的度量来推断寻求寄主的美洲 Amblyomma 成虫的自然野外和森林种群的人口结构

摘要 了解 Amblyomma americanum (L.)（孤星蜱）在不同人口类别中寻找宿主的行为模式有何不同，对于评估物种作为病原体载体的潜力至关重要。我们的目标是描述两个神秘发育群体（新换羽和越冬成虫）对 A. americanum 寻求宿主种群的相对贡献。为了确定群组身份，我们使用血红素浓度作为从田野和森林栖息地收集的蜱的生理年龄指标。在晚春和初夏出现异常高血红素浓度的蜱表明，新蜕皮的成虫在若虫充血的同一季节重新开始寻找活动。全面的，2017 年 3 月至 7 月，在密苏里州东北部的成年人活跃季节，血红素浓度显着下降。当控制捕获日期时，雄性显示出比雌性更高的平均血红素浓度，但栖息地介导的差异并不显着。在新换羽成虫的激活可行期间，没有收集到血红素浓度升高的蜱子集，这表明美洲拟南芥成虫在自然条件下经历了换羽后行为滞育。