How Do Trait-Mediated Non-lethal Effects of Predation Affect Population-Level Performance of Mosquitoes?
How Do Trait-Mediated Non-lethal Effects of Predation Affect Population-Level Performance of Mosquitoes?
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DOI：
10.3389/fevo.2019.00025
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发表时间：
2019-02-12
影响因子：
3
通讯作者：
Juliano, Steven A.
中科院分区：
文献类型：
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作者：
Chandrasegaran, Karthikeyan;Juliano, Steven A.
非致死性、性状介导的捕食效应影响猎物行为和生活史性状。研究这些影响如何反过来影响猎物的人口分布，对于理解猎物的生活史进化至关重要。蚊子是重要的病媒，通过传播一系列病原体，每年在全世界夺去数百万人的生命。几个生态因素影响幼虫和成蚊的生活史特征，产生的影响级联到种群水平的后果。很少有研究全面探讨捕食及其与资源和竞争的相互作用对蚊子幼虫、成虫和种群特征的非致死效应。了解这些相互作用是很重要的，因为捕食的影响被假设为从由幼虫竞争引起的密度依赖的影响中拯救猎物种群。以2种不同密度饲养的埃及伊蚊幼虫和3种非致死性捕食者处理的埃及伊蚊幼虫，监测其从幼虫期到成虫羽化的存活、发育时间和成虫体型，并监测成虫雌蚊在第一个淋养循环中的存活和繁殖情况。种内竞争增加了幼虫的发育时间，产生了小体成虫，并降低了幼虫暴露于掠食性化学线索的个体的繁殖力。暴露在活体捕食者的暗示下会影响雌性的体型和吸血的潜伏期。生命表性状分析表明，竞争对蚊子净繁殖率（R-0）有显著影响。竞争和捕食者处理的交互作用显著影响了种群增长率(r)和表现指数（r'）。基于数量-繁殖力关系估计种群变化率的绩效指数与r呈显著正相关，但略高估r。捕食者处理和幼虫密度对虫群世代时间（T-c）没有显著影响，这进一步表明，处理对r和r'的影响主要是对r -0影响的结果。此外，不同处理组合对幼虫发育时间、成虫体型和繁殖力的显著影响最终表现为对成虫生存和繁殖的生命表性状的影响。
Non-lethal, trait-mediated effects of predation impact prey behavior and life-history traits. Studying how these effects in turn influence prey demography is crucial to understand prey life-history evolution. Mosquitoes are important vectors that claim several million lives every year worldwide by transmitting a range of pathogens. Several ecological factors affect life-history traits of both larval and adult mosquitoes, creating effects that cascade to population-level consequences. Few studies have comprehensively explored the non-lethal effects of predation and its interactions with resources and competition on larval, adult, and population traits of mosquitoes. Understanding these interactions is important because the effects of predation are hypothesized to rescue prey populations from the effects of density-dependence resulting from larval competition. Aedes aegypti larvae reared at two different larval densities and subjected to three non-lethal predator treatments were monitored for survival, development time, and adult size through the larval stages to adult eclosion, and adult females were monitored for survival and reproduction through their first gonotrophic cycle. Intraspecific competition increased larval development time, yielded small-bodied adults, and reduced fecundity in individuals exposed to predatory chemical cues as larvae. Exposure to cues from a living predator affected both body size and latency to blood feed in females. Analysis of life-table traits revealed significant effects of competition on net reproductive rate (R-0) of mosquitoes. The interaction between competition and predator treatments significantly affected the cohort rate of increase (r) and the index of performance (r'). The index of performance, which estimates rate of population change based on the size-fecundity relationship, was significantly and positively correlated with r, but overestimated r slightly. Lack of significant effect of predator treatments and larval density on cohort generation time (T-c) further suggests that the observed effects of treatments on r and r' were largely a consequence of the effects on R-0. Also, the significant effects of treatment combinations on larval development time, adult body size and fecundity were ultimately manifested as effects on life-table traits estimated from adult survival and reproduction.