Density-dependent lifespan and estimation of life expectancy for a parasitoid with implications for population dynamics
Density-dependent lifespan and estimation of life expectancy for a parasitoid with implications for population dynamics
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DOI：
10.1007/s00442-020-04709-6
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发表时间：
2020-07
期刊：
影响因子：
2.7
通讯作者：
J. Miksanek;G. Heimpel
中科院分区：
文献类型：
--
作者：
J. Miksanek;G. Heimpel
寄生蜂的寿命受营养物质供应的影响，因此依赖寄主提供营养资源(通过寄主取食或消耗蜜露)的寄生蜂的寿命应该随着寄主密度的不同而不同。我们使用实验室测试方法，评估了一种这样的物种--中华姬蜂(Aphelinus Certus)在一系列寄主密度下的存活和繁殖情况。我们发现寄主密度与FA的寿命和繁殖力之间存在着正相关的渐近关系。这一结论得到了传统生存分析和Logistic模型的支持。本试验还利用寄生蜂的翅片磨损指数建立了绒毛危害与寄生蜂年龄之间的关系。这一指数被用来估计野外采集的寄生蜂的预期寿命，这比实验室饲养的雌性寄生蜂的预期寿命要短。最后，将寄主密度依赖的寄生蜂寿命纳入耦合方程矩阵种群模型，该模型揭示了寄主密度依赖程度的降低会导致更高的平衡寄主密度和平衡质量的变化(如稳定的极限环)。这些结果详细说明了寄主密度依赖的寄生蜂寿命这一相对未被研究的现象，并表明实验室和现场确定的寄生蜂预期寿命之间的差异对昆虫的种群动态和生物防治具有重要意义。
Parasitoid lifespan is influenced by nutrient availability, thus the lifespan of parasitoids that rely on their hosts for nutritional resources (either via host feeding or by consuming honeydew) should vary with host density. We assessed the survival and reproduction of one such species,Aphelinus certus—a parasitoid of the soybean aphid,Aphis glycines—over a range of host densities using a laboratory assay. We found a positive, asymptotic relationship between host density and the lifespan and fecundity ofA. certusthat was supported by a traditional survivorship analysis as well as a logistic model. Parasitoids from this assay were also used to develop a wing wear index relating setae damage to parasitoid age. This index was used to estimate the life expectancy of field-collected parasitoids, which was shorter than the life expectancy of laboratory-reared female parasitoids. Finally, host-density-dependent parasitoid lifespan was incorporated into a coupled-equations matrix population model that revealed that decreasing the degree of host density dependence leads to higher equilibrium host densities and changes in the quality of equilibrium (e.g. stable limit cycles). These results detail the relatively unstudied phenomenon of host-density-dependent parasitoid lifespan and suggest that differences between laboratory- and field-determined parasitoid life expectancy have important implications for population dynamics and the biological control of insects.