Dynamics of consumer-resource interactions: importance of individual attributes

We focus on models of interacting populations of consumers and resources, p articularly insect parasites (parasitoids) and hosts that incorporate indiv idual attributes. Differences among individuals can have profound effects o n population dynamics. In parasitoid-host models, invulnerable classes are stabilizing, and a short host adult stage can induce single-generation cycl es. In many parasitoids the gain to the future female parasitoid population increases with the age of the encountered host, and this can both stabiliz e the inherent 'predator-prey' cycles and induce delayed feedback cycles. M odels of predators and prey also show invulnerable stages are stabilizing, but little has been done on other age-related differences. Age structure in the consumer population is typically a source of time lags and hence is de stabilizing. We know little, however, about the dynamical effects of other age-related properties, especially of predators. Juvenile and adult predato rs often feed on different resources and this has hardly been investigated. We also investigate dynamical effects of individual properties of the resou rce population that are unrelated to age and that affect its vulnerability to attack by the consumer, e.g. vulnerability related to spatial position. Insight is gained by considering whether the effect on vulnerability is tra nsient or persistent relative to the system's time scale. Persistent, but n ot transient, differences tend to have substantial dynamical effects.