Multi-scale and antagonist selection on life-history traits in parasitoids: a community ecology perspective

1) Life-history traits within ecological communities can be influenced by regional environmental conditions (external filters) and community-wide density-dependent processes (internal filters). While traits in a regional context may converge to a narrow range of values because of environmental filtering, species belonging to a guild may present contrasting traits as a means of niche differentiation, allowing coexistence whilst exploiting the same resources. 2) To disentangle the role of external and internal filters on phenotypic diversity within ecological communities, we examined the patterns of life-history trait variation within a guild of insect parasitoids during two successive years across three contrasted regions in relation to several ecological factors. 3) By combining a mean-field approach and an analysis of phenotypic variance across organizational levels (from individual to guild), we showed that the patterns of life-history trait variation across regions are consistent wit...