Data from: Female mosquitoes disperse further when develop under predation risk

Predation is one of the strongest selective forces in nature. Organisms characterized by a complex life cycle, undergoing an ontogenetic niche shift, can reduce predation risk on natal stages by metamorphosing earlier. Yet, this anti-predatory response may incur numerous life-history-related costs. Interestingly, the consequence of larval predation risk on adult dispersal, a key trait dictating the persistence of spatially-structured populations, is largely understudied. Here, we explored the effect of larval predation risk on the life-history and dispersal characteristics of female adults in the mosquito Culex pipiens. As predicted, mosquito larvae reared in the presence of a caged larvivorous-fish metamorphosed earlier, while also suffering from reduced survival. Despite this reduction in development time, the body size of emerging females was larger, implying that more resources were allocated to increase the growth rate, probably at the expense of reduced maintenance and storage. This shift in energy allocation translated into decreased pupa and adult survival. Remarkably, the respective dispersal distance of these larger bodied females was greater. We suggest that the increase in dispersal distance allows these females to cover larger areas, while searching for oviposition sites that are safer than their natal aquatic habitat. Exploring the effects of larval conditions on adult dispersal is central for understanding the distribution of organisms with a complex life cycle in spatially heterogeneous environments, and specifically for disease transmission by mosquitoes.

捕食作用是自然界中最强烈的选择压力之一。具备复杂生活史且经历个体发育生态位转移（ontogenetic niche shift）的生物，可通过提早变态发育降低其初生生境阶段的捕食风险。然而，这类反捕食响应（anti-predatory response）往往会伴随诸多与生活史相关的代价（life-history-related costs）。值得关注的是，幼虫阶段的捕食风险对成虫扩散——这一决定空间结构化种群（spatially-structured populations）存续的关键性状——的影响，目前仍未得到充分研究。本研究以尖音库蚊（Culex pipiens）的雌性成虫为研究对象，探究了幼虫捕食风险对其生活史及扩散特征的影响。实验结果与预期一致：在笼养幼虫捕食性鱼类环境中饲养的蚊幼虫，不仅提早完成变态发育，同时存活率也有所下降。尽管发育时长得以缩短，但羽化后的雌性成虫体型却更大，这表明更多资源被投入以提升生长速率，这一过程大概率以减少维持代谢与资源储存为代价。这种能量分配（energy allocation）模式的转变，进而导致蛹期与成虫期的存活率降低。尤为值得注意的是，这类体型更大的雌性成虫的扩散距离显著增加。我们推测，扩散距离的提升使得这些雌性成虫能够覆盖更广的区域，从而在相较于其初生水生栖息地更为安全的位点寻找产卵位点（oviposition sites）。探究幼虫生存环境对成虫扩散的影响，对于理解具有复杂生活史的生物在空间异质性环境（spatially heterogeneous environments）中的分布格局，尤其是蚊传疾病的传播机制，具有核心学术意义。