The maintenance of intraspecific biodiversity: the interplay of selection on resource use and on natural enemy resistance in the pea aphid |
| |
Authors: | Julia Ferrari H. Charles J. Godfray |
| |
Affiliation: | (1) Division of Biology, NERC Centre for Population Biology, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK |
| |
Abstract: | Biodiversity has both intraspecific and interspecific components, and speciation is the process through which the former is converted to the latter. Ecological factors can cause population divergence and differentiation. In this paper, we investigate the interplay between top-down effects from natural enemies and bottom-up effects from host plants in an aphid model system. Pea aphids, Acyrthosiphon pisum, are known to form host-adapted races on Trifolium and Medicago. Here, replicate clones of pea aphids collected from a broader set of five host plant genera are screened for their performance on the same set of host plants and also for their resistance to four natural enemies: the parasitoids Aphidius eadyi and Aphidius ervi, and the entomopathogenic fungi Pandora (=Erynia) neoaphidis and Zoophthora phalloides. The populations showed clear adaptation to their host plant from which they were collected, but they also performed well on Vicia. Performance on the other three plant species was poor. The aphid population collected from Lotus was significantly better at defending itself against the parasitoid A. eadyi, and there was a tendency for the clones from Trifolium to be resistant to the pathogen P. neoaphidis. These patterns highlight the importance of understanding the ecological processes influencing speciation in the context of the web of ecological adaptations within which a species is embedded. |
| |
Keywords: | Genetic variation Host use Intraspecific biodiversity Resistance to natural enemies Pea aphid |
本文献已被 SpringerLink 等数据库收录! |
|