Generalist predators with broadly overlapping niches commonly coexist on seemingly identical sets of prey. Here, we provide empirical demonstration that predators can differentially exploit fine-grained niches generated by variable, heritable and selective defences within a single prey species. Some, but not all, clones of the aphid Aphis craccivora are toxic towards the dominant invasive predatory ladybeetle, Harmonia axyridis. However, other less competitive ladybeetle species are not affected by the aphid’s toxic trait. In laboratory and open field experiments, we show: (i) that subdominant ladybeetle species were able to exploit the toxic aphids, benefitting from the suppression of the dominant predator; and (ii) that this narrow-spectrum toxicity can function as an anti-predator defence for the aphid, but depends on enemy community context. Our results demonstrate that niche differentiation among generalist predators may hinge upon previously underappreciated heritable variation in prey defence, which, in turn, may promote diversity and stability of enemy communities invaded by a dominant predator.
|Journal||Proceedings of the Royal Society B: Biological Sciences|
|State||Published - May 30 2018|
Bibliographical noteFunding Information:
This work was supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under Awards no. 2014-67013-21576 and Hatch no. 0224651, as well as the University of Kentucky.
© 2018 The Author(s) Published by the Royal Society. All rights reserved.
- Anti-predator defence
- Heritable intraspecific variation
- Invasive species
- Niche differentiation
- Predator–prey interactions
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology (all)
- Immunology and Microbiology (all)
- Environmental Science (all)
- Agricultural and Biological Sciences (all)