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.