Interacting Selective Pressures in Conifer-Bark Beetle Systems: A Basis for Reciprocal Adaptations?

Kenneth F. Raffa, Alan A. Berryman
1987 American Naturalist  
Classical models of plant-insect coevolution have emphasized that related species of insects frequently exploit closely related groups of plants (Ehrlich and Raven 1964; Benson et al. 1976 ). Implicit in this concept is a series of adaptations and counteradaptations by both the host and the parasite. Such models, although descriptive of broad patterns in evolutionary time, do not address the ecological factors affecting individual fitness nor the genetic capacity for change. The purpose of this
more » ... The purpose of this report is to concentrate on one aspect of coevolution, the phenotypic traits affecting plant and insect fitness, in one type of interaction. This is an essential first step before the heritability of the relevant features can be quantified. Bark beetles (Coleoptera: Scolytidae), particularly species that colonize the stems of living trees, provide a useful model system for evaluating the extent to which reciprocal selective pressures may prevail in host-parasite interactions (Sturgeon 1979; Mitton and Sturgeon 1982a,b). Several aspects of their biology allow direct evaluation of how various traits affect plant and insect success.
doi:10.1086/284633 fatcat:pkx2e6kb5bgxvniw4eu7tckfam