Aphid Facultative Symbionts Reduce Survival of the Predatory Lady Beetle Hippodamia convergens

Costopolous, Kelly, Department of Biology, Wayne Rollins Research Center, Emory University
Kovacs, Jennifer L., Department of Biology, Spelman College
Kamins, Alexandra, Department of Biology, Wayne Rollins Research Center, Emory University
Gerardo, Nicole M., Department of Biology, Wayne Rollins Research Center, Emory University

2014-02-20

2010-2019

BACKGROUND: Non-essential facultative endosymbionts can provide their hosts with protection from parasites, pathogens, and predators. For example, two facultative bacterial symbionts of the pea aphid (Acyrthosiphon pisum), Serratia symbiotica and Hamiltonella defensa, protect their hosts from parasitism by two species of parasitoid wasp. Previous studies have not explored whether facultative symbionts also play a defensive role against predation in this system. We tested whether feeding on aphids harboring different facultative symbionts affected the fitness of an aphid predator, the lady beetle Hippodamia convergens. RESULTS: While these aphid faculative symbionts did not deter lady beetle feeding, they did decrease survival of lady beetle larvae. Lady beetle larvae fed a diet of aphids with facultative symbionts had significantly reduced survival from egg hatching to pupation and therefore had reduced survival to adult emergence. Additionally, lady beetle adults fed aphids with facultative symbionts were significantly heavier than those fed facultative symbiont-free aphids, though development time was not significantly different. CONCLUSIONS: Aphids reproduce clonally and are often found in large groups. Thus, aphid symbionts, by reducing the fitness of the aphid predator H. convergens, may indirectly defend their hosts clonal descendants against predation. These findings highlight the often far-reaching effects that symbionts can have in ecological systems. KEYWORDS: Symbiosis; Mutualism; Symbiont-conferred protection; Serratia symbiotica; Hamiltonella defensa; Pea aphid; Acyrthosiphon pisum; Predation; Defensive mutualism; Protective symbiosis

text

application/pdf

articles

BMC Ecology

Department of Biology

http://www.biomedcentral.com/1472-6785/14/5

10.1186/1472-6785-145

http://hdl.handle.net/20.500.12322/sc.fac.pubs:2014_kovacs

http://rightsstatements.org/vocab/InC/1.0/