模拟 questing 行为和宿主可用性对蜱虫种群动态的影响
A Model of Annual Tick Population Density in the Eastern United States as a Function of Questing Behavior and Host Availability
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中文总结 AI 辅助
研究模拟 questing 行为和宿主可用性对蜱虫种群动态的影响，构建阶段结构非线性差分方程组，通过比率依赖的宿主附着体现生物事件序列，经参数化和分析得出种群动态受群体增长与宿主附着机会平衡支配的结论。
中文摘要 AI 辅助
肩突硬蜱传播多种人类病原体，了解其种群动态对评估和预测疾病风险至关重要。蜱虫种群统计学依赖于一系列生物事件，包括繁殖、非宿主生存以及成功附着宿主吸血，这些都受宿主群落和 questing 行为影响。本文通过比率依赖的宿主附着构建了一个包含这些事件序列的阶段结构非线性差分方程组。该模型针对美国东北部和东南部生态系统参数化。分析和数值分岔分析表明，随着人口统计学繁殖数增加，系统呈现 +1/-1 分岔对，产生稳定正存在不动点和不稳定 2 周期。比率依赖的取食成功通过限制成功取食来限制种群规模，questing 行为决定宿主接触频率和组成，进而影响成功取食。结果表明长期蜱虫种群结果受群体增长和宿主附着机会之间平衡的支配。
英文摘要
Understanding the ecological processes that regulate populations of the blacklegged tick, Ixodes scapularis, is essential for explaining regional differences in tick abundance and the risk of tick-borne diseases. In this study, we develop a stage-structured nonlinear system of difference equations by ordering and composing the seasonal biological events that govern tick and host life cycles. The model incorporates ratio-dependent host-attachment, allowing host-finding success to depend jointly on host availability and tick abundance. Parameter estimates from both northeastern and southeastern ecosystems in the United States are used to examine how regional differences in host community composition and questing behavior influence tick population dynamics. Analysis shows that a $+1$/$-1$ bifurcation pair occurs at the demographic persistence threshold, producing an exchange of stability between the extinction and positive fixed points together with the emergence of an unstable cohort-based 2-cycle. Quantitative results show that ratio-dependent host-finding success limits population growth by restricting successful feeding, while questing behavior alters both the frequency and composition of host encounters. Together, these mechanisms regulate tick persistence and long-term abundance, providing a demographic foundation for understanding variation in tick abundance and Lyme disease risk.
