Oecologia

, Volume 166, Issue 3, pp 723–730

Predator biodiversity increases the survivorship of juvenile predators

Community ecology - Original Paper

DOI: 10.1007/s00442-010-1891-y

Cite this article as:
Takizawa, T. & Snyder, W.E. Oecologia (2011) 166: 723. doi:10.1007/s00442-010-1891-y

Abstract

When predator biodiversity strengthens herbivore suppression, the pattern generally is attributed to interspecific complementarity. However, the relaxation of intraspecific interference within diverse communities has received less attention as an underlying factor, and most experiments to date span much less than one predator generation. Here, working with a community of aphid predators, we compared the survivorship of juvenile predators embedded within diverse versus single-species communities of adult predators. We found that greater predator diversity improved juvenile survivorship for three of four predator taxa (the lady beetles Hippodamia convergens and Coccinella septempunctata, and the bug Nabisalternatus; but not the small bug Geocoris bullatus), whereas survivorship was relatively low when juveniles foraged among only conspecific adults. When aphid densities differed they were lowest for the diverse treatment, and so resource availability could not explain differences in juvenile survivorship. Instead, feeding trials indicated that cannibalism generally posed a greater risk to juveniles than did intraguild predation (with Geocoris again the exception). Our results suggest that the dilution of intraspecific interference may play an important, and perhaps underappreciated, role in shaping predator diversity effects. Furthermore, relatively strong cannibalism but weak intraguild predation has the potential to project diversity effects forward into subsequent generations.

Keywords

Predator–prey interactions Cannibalism Intraguild predation Species richness Biological control 

Supplementary material

442_2010_1891_MOESM1_ESM.doc (99 kb)
Supplementary material 1 (DOC 99 kb)

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.Department of EntomologyWashington State UniversityPullmanUSA