Data from: Predator diversity reduces habitat colonization by mosquitoes and midges

Changes in predator diversity via extinction and invasion are increasingly widespread and can have important ecological and socio-economic consequences. Anticipating and managing these consequences requires understanding how predators shape ecological communities. Previous predator biodiversity research has focused on post-colonization processes. However, predators can also shape communities by altering patterns of prey habitat selection during colonization. The sensitivity of this non-consumptive top down mechanism to changes in predator diversity is largely unexamined. To address this gap, we examined patterns of dipteran oviposition habitat selection in experimental aquatic habitats in response to varied predator species richness while holding predator abundance constant. Caged predators were used in order to disentangle behavioural oviposition responses to predator cues from potential post-oviposition consumption of eggs and larvae. We hypothesized that because increases in predator richness often result in greater prey mortality than would be predicted from independent effects of predators, prey should avoid predator-rich habitats during colonization. Consistent with this hypothesis, predator-rich habitats received 48% fewer dipteran eggs than predicted, including 60% fewer mosquito eggs and 38% fewer midge eggs. Our findings highlight the potentially important links between predator biodiversity, prey habitat selection and the ecosystem service of pest regulation.通过物种灭绝与生物入侵引发的捕食者多样性变化正愈发普遍，且可能带来重大的生态与社会经济影响。要预判并管控此类影响，需明晰捕食者如何塑造生态群落结构。以往针对捕食者生物多样性的研究多聚焦于定殖后过程，但捕食者亦可通过改变猎物在定殖阶段的生境选择模式来塑造群落。目前鲜有针对该非消耗性下行调控（non-consumptive top-down）机制对捕食者多样性变化敏感性的相关研究。为填补这一研究空白，我们在维持捕食者丰度恒定的前提下，设置不同捕食者物种丰富度梯度，在实验水生生境中探究双翅目昆虫的产卵生境选择模式。本研究采用笼养捕食者，以此将猎物对捕食者信号的产卵行为响应，与产卵后卵粒及幼虫可能遭遇的捕食消耗效应分离开来。我们提出如下假说：由于捕食者丰富度提升往往会导致比单一捕食者独立效应之和更高的猎物死亡率，因此猎物在定殖阶段应规避捕食者富集的生境。实验结果与该假说一致：捕食者富集生境中的双翅目昆虫产卵量较预期低48%，其中蚊卵数量减少60%，蠓卵数量减少38%。本研究结果揭示了捕食者生物多样性、猎物产卵生境选择与害虫调控这一生态系统服务之间潜在的重要关联。