Plant genetics shapes inquiline community structure across spatial scales

Abstract

Recent research in community genetics has examined the effects of intraspecific genetic variation on species diversity in local communities. However, communities can be structured by a combination of both local and regional processes and to date, few community genetics studies have examined whether the effects of instraspecific genetic variation are consistent across levels of diversity. In this study, we ask whether host-plant genetic variation structures communities of arthropod inquilines within distinct habitat patches--rosette leaf galls on tall goldenrod (Solidago altissima). We found that genetic variation determined inquiline diversity at both local and regional spatial scales, but that trophic-level responses varied independently of one another. This result suggests that herbivores and predators likely respond to heritable plant traits at different spatial scales. Together, our results show that incorporating spatial scale is essential for predicting the effects of genetically variable traits on different trophic levels and levels of diversity within the communities that depend on host plants.

Genetically based population variation in aphid association with ants and predators

“…A number of past studies have documented the importance of plant genotype identity for arthropod community structure (Crutsinger et al 2009;Gassmann and Hare 2005;Johnson 2008;Johnson and Agrawal 2005;Wimp and Whitham 2001). This study provides important additional evidence that such effects can similarly be attributed to animals generally (Ferrari and Godfray 2006;Ferrari et al 2001;Harmon et al 2009;Hazell and Fellowes 2009;Palkovacs and Post 2008;Post and Palkovacs 2009), and provides the first documentation of such effects on antaphid interactions.…”

“…Most of this work has studied plants, where genotype identity can explain much of the variation in arthropod species composition (Crutsinger et al 2009;Johnson and Agrawal 2005;Wimp and Whitham 2001) and can mediate the interactions among resident arthropod species (Gassmann and Hare 2005;Johnson 2008;. Because such extended phenotypes appear to be common, there is an emerging view that intra-specific variation can have important consequences for fundamental aspects of community structure.…”

Aphid and ladybird beetle abundance depend on the interaction of spatial effects and genotypic diversity

“…For example, arthropod abundance in a given patch may be similar to arthropod abundance in neighboring patches (irrespective of host-plant genotype) due to interactions among arthropod populations occurring at scales larger than the focal plot (Crutsinger et al 2009a;Tack et al 2010). Consequently, the distribution of arthropods in a patchy, genotypically heterogeneous environment will likely be shaped by both plant genotype identity and spatial interactions among arthropod populations on different patches of plants.…”

“…Consequently, the distribution of arthropods in a patchy, genotypically heterogeneous environment will likely be shaped by both plant genotype identity and spatial interactions among arthropod populations on different patches of plants. While a few studies have begun to explore the interaction of spatial effects and genotype identity on biodiversity (Bangert et al 2008;Crutsinger et al 2009a), to our knowledge, no study has examined whether genotypic diversity interacts with neighborhood effects among nearby plots to determine arthropod abundance.…”

Genetic variation, predator–prey interactions and food web structure

“…Usually, when community genetics studies extend beyond one trophic level, these focus on how genetic variation among herbivores or their host plants affects herbivore performance [1,2] or on the bottom-up effects of plant genetic variation on herbivore and predatory arthropods ( [3][4][5]; reviewed in [6,7]). One exceptional study, however, focused on genetic variation in a ladybird predator [8], and how an indirect effect of plants mediated by the ladybird's prey (aphids) could affect the phenotype and performance of different ladybird genotypes, demonstrating genetic variation in the response of ladybird traits to an indirect ecological (bottom-up) effect.…”