title: The effect of host plants on genotype variability in fitness and honeydew composition of Aphis fabae.
abstract: Aphid species can be polyphagous, feeding on multiple host plants across genera. As host plant species can have large variation in their phloem composition, this can affect aphid fitness and honeydew composition. Previous research showed significant intraspecific genotype variation in the composition of the honeydew carbohydrates of the black bean aphid Aphis fabae, with the ant attractant trisaccharide melezitose showing especially large variation across different genotypes. In this study, we test if variation in melezitose and carbohydrate composition of aphid honeydew could be linked to the adaptation of specific aphid genotypes to particular host plants. To this end, 4 high and 5 low melezitose secreting genotypes of the black bean aphid Aphis fabae were reared on 4 common host plants: broad bean, goosefoot, beet, and poppy. The carbohydrate composition, and in particular melezitose secretion, showed important aphid genotype and host plant interactions, with some genotypes being high melezitose secreting on 1 host plant but not on another. However, the interaction effects were not paralleled in the fitness measurements, even though there were significant differences in the average fitness across the different host plants. On the whole, this study demonstrates that aphid honeydew composition is influenced by complex herbivore-plant interactions. We discuss the relevance of these findings in the context of ant-aphid mutualisms and adaptive specialization in aphids.
authors.affiliation: Laboratory of Socioecology and Social Evolution, Biology Department, Zoological Institute, University of Leuven, Leuven, Belgium.
authors.forename: Sharon
authors.initials: S
authors.lastname: Schillewaert
authors.affiliation: Laboratory of Socioecology and Social Evolution, Biology Department, Zoological Institute, University of Leuven, Leuven, Belgium.|Institut Pasteur du Cambodge, Unité d'Epidémiologie Moléculaire du Paludisme, Phnom Penh, Cambodia.
authors.forename: Amélie
authors.initials: A
authors.lastname: Vantaux
authors.affiliation: Laboratory of Molecular Plant Biology, Biology Department, University of Leuven, Leuven, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Van den Ende
authors.affiliation: Laboratory of Socioecology and Social Evolution, Biology Department, Zoological Institute, University of Leuven, Leuven, Belgium.
authors.forename: Tom
authors.initials: T
authors.lastname: Wenseleers
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D001000:Ants; D001042:Aphids / Q000502:physiology*; D050260:Carbohydrate Metabolism; D056084:Genetic Fitness; D049810:Genetic Speciation; D005838:Genotype; D060434:Herbivory; D019684:Magnoliopsida; D013559:Symbiosis; D014312:Trisaccharides / Q000378:metabolism*
chemical_list: D014312:Trisaccharides; C005190:melezitose
keywords: Aphis fabae; Melezitose; aphids; ecological specialization; fitness; honeydew; host plants; polyphagous