Research Interests

     Research has concentrated on insect ecology: plant and herbivore interactions, multiple-trophic-level interactions, population dynamics, and the distribution and abundance of insects. The central theme is captured in the Phylogenetic Constraints Hypothesis (Price et al. 1990, Price 1994, and the book on Macroevolutionary Theory on Macroecological Patterns, Price 2003). This hypothesis argues that evolved characters of organisms such as morphology, behavior, and life history, influence strongly their ecological relationships, including the way that populations fluctuate through time and space. Evolved traits dictate how an insect will respond to host plant module quality, and if it selects vigorous plant modules - The Plant Vigor Hypothesis (Price 1991) - or old and senescing modules, or if it is unselective. Phylogenetic constraints are held in common across insect lineages that have migrated across the globe, so that their member's ecology remains similar, whether in temperate or tropical latitudes. Broad comparative approaches are adopted in research based on the taxonomic richness of the insects.

    Since 1979 field research has focused on the ecology of sawflies, particularly gall-inducing species, and other groups of gall-inducing insects. Long-term population studies on the arroyo willow stem-galling sawfly, Euura lasiolepis (Hymenoptera: Tenthredinidae) feeding on the arroyo willow, Salix lasiolepis (Salicaceae), show that dynamics are driven by bottom-up effects, from precipitation to host-plant growth and quality, to the ovipositional preference of females for vigorous plant modules, to larval performance (Price and Hunter 2005). This strong ovipositional preference of adult females for vigorous plant modules, linked to high larval performance on such modules, appears to be a general relationship for many sawflies, other gall-inducing groups, and many other kinds and lineages of insect herbivores (Price 2003).

    Studies on Euura lasiolepis that highlighted the constraints on the resources available for successful reproduction, and the general nature of these constraints, revealed the strong impact of resource quality on distribution, abundance and population dynamics. This limited populations to be latent in their dynamics and non-outbreaking as species (Price et al. 1990, Price 1994, 2003). Their dynamics contrasted with those of outbreaking species because of different phylogenetic constraints, resulting in lack of ovipositional preferences for vigorous plant modules of high quality for larvae, and generalized feeding capability of larvae. Consequently, densities could rise until damage to crops and forests resulted from these outbreaking species with eruptive population dynamics. Such patterns as species with latent or eruptive population dynamics are determined by differences in phylogenetic constraints, which persist during adaptive radiation of lineages around the world.

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