Present address: Christoph Vorburger, Institute of Integrative Biology, ETH Zürich, 8092 Zürich, Switzerland, and EAWAG, Swiss Federal Institute of Aquatic Research and Technology, 8600 Dübeudorf, Switzerland.
Ample genetic variation but no evidence for genotype specificity in an all-parthenogenetic host–parasitoid interaction
Article first published online: 14 JAN 2010
© 2009 The Authors. Journal Compilation © 2009 European Society For Evolutionary Biology
Journal of Evolutionary Biology
Volume 23, Issue 3, pages 578–585, March 2010
How to Cite
SANDROCK, C., GOUSKOV, A. and VORBURGER, C. (2010), Ample genetic variation but no evidence for genotype specificity in an all-parthenogenetic host–parasitoid interaction. Journal of Evolutionary Biology, 23: 578–585. doi: 10.1111/j.1420-9101.2009.01925.x
- Issue published online: 25 JAN 2010
- Article first published online: 14 JAN 2010
- Received 4 October 2009; revised 29 November 2009; accepted 8 December 2009
- Aphis fabae;
- genotype-by-genotype interactions;
- host–parasitoid coevolution;
- Lysiphlebus fabarum;
Antagonistic coevolution between hosts and parasites can result in negative frequency-dependent selection and may thus be an important mechanism maintaining genetic variation in populations. Negative frequency-dependence emerges readily if interactions between hosts and parasites are genotype-specific such that no host genotype is most resistant to all parasite genotypes, and no parasite genotype is most infective on all hosts. Although there is increasing evidence for genotype specificity in interactions between hosts and pathogens or microparasites, the picture is less clear for insect host–parasitoid interactions. Here, we addressed this question in the black bean aphid (Aphis fabae) and its most important parasitoid Lysiphlebus fabarum. Because both antagonists are capable of parthenogenetic reproduction, this system allows for powerful tests of genotype × genotype interactions. Our test consisted of exposing multiple host clones to different parthenogenetic lines of parasitoids in all combinations, and this experiment was repeated with animals from four different sites. All aphids were free of endosymbiotic bacteria known to increase resistance to parasitoids. We observed ample genetic variation for host resistance and parasitoid infectivity, but there was no significant host clone × parasitoid line interaction, and this result was consistent across the four sites. Thus, there is no evidence for genotype specificity in the interaction between A. fabae and L. fabarum, suggesting that the observed variation is based on rather general mechanisms of defence and attack.