DOI: 10.5061/dryad.5j329
title: Data from: Keystone nonconsumptive effects within a diverse predator community

description: The number of prey killed by diverse predator communities is determined by
 complementarity and interference among predators, and by traits of
 particular predator species. However, it is less clear how predators'
 nonconsumptive effects (NCEs) scale with increasing predator biodiversity.
 We examined NCEs exerted on Culex mosquitoes by a diverse community of
 aquatic predators. In the field, mosquito larvae co-occurred with
 differing densities and species compositions of mesopredator insects; top
 predator dragonfly naiads were present in roughly half of surveyed water
 bodies. We reproduced these predator community features in artificial
 ponds, exposing mosquito larvae to predator cues and measuring resulting
 effects on mosquito traits throughout development. Nonconsumptive effects
 of various combinations of mesopredator species reduced the survival of
 mosquito larvae to pupation, and reduced the size and longevity of adult
 mosquitoes that later emerged from the water. Intriguingly, adding single
 dragonfly naiads to ponds restored survivorship of larval mosquitoes to
 levels seen in the absence of predators, and further decreased adult
 mosquito longevity compared with mosquitoes emerging from mesopredator
 treatments. Behavioral observations revealed that mosquito larvae
 regularly deployed “diving” escape behavior in the presence of the
 mesopredators, but not when a dragonfly naiad was also present. This
 suggests that dragonflies may have relaxed NCEs of the mesopredators by
 causing mosquitoes to abandon energetically costly diving. Our study
 demonstrates that adding one individual of a functionally unique species
 can substantially alter community-wide NCEs of predators on prey. For
 pathogen vectors like mosquitoes, this could in turn influence disease
 dynamics.
description: Mesocosm
 experimentThese data were
 collected during the mesocosm experiment described in "Keystone
 nonconsumptive effects within a diverse predator community" by
 Meadows et al. 2017. A description of each column follows: 1- Source:
 treatment groups; 2- Exposure: C=caged mosquito larvae, NC= exposed
 mosquito larvae; 3- Sex: sex could only be determined for (most) adult
 mosquitoes; 4-Tp: days to pupation i.e. larval development period; 5-
 Longevity: adult mosquito longevity (eclosion-death, in days); 6- Density:
 total number of predators in mesocosm; 7- Aquarius: number of Aquarius in
 mesocosm; 8- Beetle: number of Agabus + Tropisternus beetles in mesocosm;
 9- Notonecta: number of Notonecta in mesocosm; 10- Aeshna: was Aeshna
 present in the community? Yes or No for predator treatments, Control if no
 predator (or Aeshna, by extension); 11-H: Shannon's H calculation for
 predator community evenness (99 entered for control to easily subset
 predator only treatments); 12- Cslong: sex-standardized adult longevity
 (see Meadows et al. Supp Info for calculation); 13- Winglength: adult
 winglength (in mm)Meadows_et_al_2017.csvbehavior experimentThese data were collected from the behavior experiment described in Meadows et al. 2017. Column descriptions are as follows: 1- Treatment: indicates predator community composition; 2- ID: separates replicates of treatments; 3- Obs: observation period/replicate; 4- Larvae: the number of larvae remaining at each observation period; 5- Diving: the proportion of larvae observed diving at least once during the observation period; 6- Aeshna: was Aeshna present in the community (Y= yes, N= no, C= control (no predators present); 7- ActiveP: 1 if a mesopredator was active during the observation period, 0 otherwise.behavior.csv