GOSSYM is a physiologically detailed model of plant growth rich in mechanistic processes. GOSSYM simulates a single average plant and generalizes its results to represent a population of plants by including functions that represent the average response for a population. TEXCIM is an assemblage of insect simulation models of population dynamics which have been integrated into a unique management and planning system. Our research addressed the following: 1) the integration of a single plant-based system with population level models of insect pests and predators (present approach and expected enhancements); 2) Modelling the response of the plant to insect damage (fruit-feeders, leaf-feeders, leaf-suckers, terminal-feeders), including the phenomenon of compensation; 3) the problem of sampling for plant phenology and sampling for insects (differences, similarities, and an approach to integration and enhancement through Bayesian-based methods); 4) integration of databases and integration of software; 5) verification and validation of an integrated system.