Uncovering mechanisms behind mosquito seasonality by integrating mathematical models and daily empirical population data: Culex pipiens in the UK
Uncovering mechanisms behind mosquito seasonality by integrating mathematical models and daily empirical population data: Culex pipiens in the UK
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DOI：
10.1186/s13071-019-3321-2
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发表时间：
2019-02-07
影响因子：
3.2
通讯作者：
White, Steven M.
中科院分区：
文献类型：
--
作者：
Ewing, David A.;Purse, Bethan V.;White, Steven M.
背景由于环境变量与媒介和病原体生命周期之间的密切联系，许多蚊媒疾病表现出明显的季节性。此外，一系列密度依赖和密度无关的生物和非生物过程影响蚊子种群的物候，对媒介动力学和疾病传播具有潜在的巨大连锁效应。虽然人们知道密度无关和密度相关的过程会影响季节性人口水平，但尚不清楚这些过程如何在时间上相互作用以形成人口高峰和低谷。由于缺乏用于验证的高分辨率数据，以及参数化密度依赖过程的困难，媒介动力学模型可能很难估计丰度，这对我们预测媒介传播疾病爆发的能力产生了连锁反应。结果我们于 2015 年在英格兰南部的一个现场提供了一个丰富的数据集，描述了淡色库蚊（西尼罗河病毒的广泛传播媒介）每个生命阶段的季节性丰度模式。未成熟阶段的丰度每周测量 3 次，同时成虫陷阱每周运行四个晚上。该数据集与预测 Cx 的现有延迟微分方程模型集成。 pipiens 季节性丰度，以提高对观察到的季节性丰度模式的理解。在我们的现场，我们的模型拟合结果表明，对蚊子幼虫的种间捕食和与温度相关的幼虫死亡率共同成为整个活动季节种群调节的主要来源，而资源竞争是幼虫死亡率相对较小的来源。结论该模型表明，与密度无关的死亡率和种间捕食相互作用，塑造了永久水生栖息地中蚊子季节性丰度的模式，我们认为，在高降雨量创造短暂栖息地的情况下，对资源的竞争可能很重要。此外，我们强调了如果要从这些模型中得出可靠的推论，特别是在考虑蚊子控制和媒介传播疾病传播时，用来自感兴趣物种的所有生命阶段的数据来挑战种群丰度模型的重要性。
BackgroundMany mosquito-borne diseases exhibit substantial seasonality, due to strong links between environmental variables and vector and pathogen life-cycles. Further, a range of density-dependent and density-independent biotic and abiotic processes affect the phenology of mosquito populations, with potentially large knock-on effects for vector dynamics and disease transmission. Whilst it is understood that density-independent and density-dependent processes affect seasonal population levels, it is not clear how these interact temporally to shape the population peaks and troughs. Due to this, the paucity of high-resolution data for validation, and the difficulty of parameterizing density-dependent processes, models of vector dynamics may poorly estimate abundances, which has knock-on effects for our ability predict vector-borne disease outbreaks.ResultsWe present a rich dataset describing seasonal abundance patterns of each life stage of Culex pipiens, a widespread vector of West Nile virus, at a field site in southern England in 2015. Abundance of immature stages was measured three times per week, whilst adult traps were run four nights each week. This dataset is integrated with an existing delay-differential equation model predicting Cx. pipiens seasonal abundance to improve understanding of observed seasonal abundance patterns. At our field site, the outcome of our model fitting suggests interspecific predation on mosquito larvae and temperature-dependent larval mortality combine to act as the main sources of population regulation throughout the active season, whilst competition for resources is a relatively small source of larval mortality.ConclusionsThe model suggests that density-independent mortality and interspecific predation interact to shape patterns of mosquito seasonal abundance in a permanent aquatic habitat and we propose that competition for resources is likely to be important where periods of high rainfall create transient habitats. Further, we highlight the importance of challenging population abundance models with data from across all life stages of the species of interest if reliable inferences are to be drawn from these models, particularly when considering mosquito control and vector-borne disease transmission.