Antipredatory behavioral responses tend to be energetically expensive, and prey species thus need to resolve trade-offs between these behaviors and other activities such as foraging and mating. While these trade-offs have been well-studied across taxa, less is known about how costs and benefits vary in different life-history contexts, and associated consequences. To address this question, we compared responses of the yellow fever mosquito (Aedes aegypti [Diptera: Culicidae]) to predation threat from guppy (Poecilia reticulata [Cyprinodontiformes: Poeciliidae]) across two life-history stages-larvae (data from previous study) and pupae (from this study). Pupae are motile but do not feed and are comparable to larvae in terms of behavior. To understand how physiological costs affect the threat sensitivity of pupae, we used sex (with size as a covariate) as a proxy for stored energy reserves, and quantified movement and space use patterns of male (small-sized) and female (large-sized) pupae when exposed to predation threat. We found that pupae did not alter movement when exposed to predator cues but instead altered spatial use by spending more time at the bottom of the water column. We found no effect of pupa sex (or size) on the behavioral responses we measured. We conclude that pupa behavior, both antipredatory and otherwise, is primarily targeted at minimizing energy expenditure, as compared with larval behavior, which appears to balance energy expenditure between the opposing pressures of foraging and of avoiding predation. We suggest that antipredatory defenses in metamorphosing prey are modulated by varying energetic trade-offs associated with different life-history stages.

中文翻译：

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蚊蛹对非致命捕食威胁的反捕食反应——跨越生命历史阶段的行为可塑性

反掠夺行为反应往往在能量上是昂贵的，因此猎物物种需要解决这些行为与其他活动（如觅食和交配）之间的权衡。虽然这些权衡已在整个分类群中得到了充分研究，但人们对成本和收益在不同生活史背景下的差异以及相关后果知之甚少。为了解决这个问题，我们比较了黄热病蚊子（埃及伊蚊 [双翅目：库丽科]）对来自孔雀鱼（Poecilia reticulata [Cyprinodontiformes：Poeciliidae]）的捕食威胁的反应，跨越两个生活史阶段 - 幼虫（来自先前研究的数据）和蛹（来自本研究）。蛹能动但不进食，在行为方面与幼虫相当。要了解生理成本如何影响蛹的威胁敏感性，我们使用性别（以大小作为协变量）作为储存能量储备的代理，并量化了雄性（小型）和雌性（大型）蛹在受到捕食威胁时的运动和空间使用模式。我们发现蛹在暴露于捕食者线索时并没有改变运动，而是通过在水柱底部花费更多时间来改变空间使用。我们发现蛹性别（或大小）对我们测量的行为反应没有影响。我们得出的结论是，与幼虫行为相比，蛹的反捕食行为和其他行为主要旨在最大限度地减少能量消耗，幼虫行为似乎在觅食和避免捕食的相反压力之间平衡了能量消耗。