Biotic Interactions Between Saproxylic Insect Species

Abstract

A better understanding of biotic interactions in species-rich saproxylic insect communities can provide essential information for biodiversity conservation and ecosystem functioning enhancement. Evidence in the literature mainly relates to beetle species, in particular scolytines, at tree-or even smaller-spatial scales and mostly refers to antagonistic interactions. We here present an overview of competition, predation/parasitism and facilitation among saproxylic insects. We first underline segregation patterns between wood consumers, resulting from competition processes, such as spatial and temporal resource partitioning, competitive displacement via interference and even enemy-mediated ``apparent competition.{''} Considering natural history facts about prey-predator and host-parasitoid relationships, we then emphasize processes regulating the pressure of top-down influences on prey/host population dynamics. Facilitative interactions, including mechanisms of habitat location, creation, and improvement, are thereafter considered. The implications of some findings for pest management strategies (biocontrol, semiochemical-based methods) and for ecosystem functioning (deadwood decomposition) are highlighted meanwhile. Approaches based on life-history traits or indirect mediated interactions finally move the focus from the responses of paired species to multispecific community-level changes. Ecological network analysis should help increase our understanding of biotic interactions and investigate the consequences of environmental changes for those interactions and ecosystem functioning.