The tea leaf roller (Caloptilia theivora) is one of the harmful pests of tea plants in western and southern Japan. This insect pest seriously reduces a quality of manufactured tea. Knowledge of the phenology of C. theivora may allow prediction of the timing of appearance of particular developmental stages in the field, which can provide a well-timed control method. A key factor regulating the lifecycle of insect pest is temperature － because insects are cold-blooded, the growth and development of adults, larvae, pupae, and eggs is strongly dependent on temperature. Since temperatures may vary widely from year to year, the timing of appearance of insect pest will vary every year, which makes the pest’s forecasting and management difficult. One way to further our understanding of the phenology of C. theivora is to develop a model of population dynamics in which temperature-dependent development is explicitly described. This study represents the comprehensive attempt to model C. theivora populations in the field using field temperature data, and the model predictions are compared with observed captures in pheromone traps at the experimental site of Kagoshima tea experiment research station in Chiran, Kagoshima, Japan. Based on the results, we provide general discussion about good management and monitoring strategies of insect pests.

We study a Markov chain model for the land use dynamics in forest ecosystems in which both socioeconomic and ecological factors affecting human decision making are represented in an integrated manner. Assumptions are: a forest is composed of many land parcels, each of which is in one of several potential land-use states, such as natural forest, logging forest, and abandoned secondary forest. Each land parcel changes its state stochastically with transition probability controlled by the decision making of landowners. Landowners make their land-use decision by comparing different land-use options in terms of the cumulative expected profits in future projected to the present time, named “present values". We analyzed the land-use composition at equilibrium and show that the long-term perspective and the effort to accelerate the speed of forest are important for successful land management.