PHYLOGENETIC CONSTRAINTS, ADAPTIVE SYNDROMES, AND EMERGENT PROPERTIES- FROM INDIVIDUALS TO POPULATION-DYNAMICS

The hypothesis is developed that there are causal linkages in evolved insect herbivore life histories and behaviors from phylogenetic constr ains to adaptive syndromes to the emergent properties involving ecolog ical interactions and population dynamics. Thus the argument is develo ped that the evolutionary biology of a species predetermines its curre nt ecology. Phylogenetic Constraints refer to old characters in the ph ylogeny of a species and a group of species which set limits on the ra nge of life history patterns and behaviors that can evolve. For exampl e, a sawfly is commonly limited to oviposition in soft plant tissue, w hile plants are growing rapidly. Adaptive Syndromes are evolutionary r esponses to the phylogenetic constraints that minimize the limitations and maximize larval performance. Such syndromes commonly involve deta ils of female ovipositional behavior and how individuals make choices for oviposition sites relative to plant quality variation which maximi ze larval survival. Syndromes also involve larval adaptations to the k inds of choices females make in oviposition. The evolutionary biology involved with phylogenetic constraints and adaptive syndromes commonly predetermines the ecological interactions of a species and its popula tion dynamics. Therefore, these ecological interactions are called Eme rgent Properties because they are natural consequences of evolved morp hology, behavior, and physiology. They commonly strongly influence the three-trophic-level interactions among host plants, insect herbivores , and carnivores, and the relative forces of bottom-up and top-down in fluences in food webs. The arguments are supported using such examples as galling sawflies and other gallers, shoot-boring moths and beetles , budworms, and forest Macrolepidoptera. The contrasts between outbrea k or eruptive species and uncommon and rare species with latent popula tion dynamics are emphasized.