Range expansion of forest pest populations by using the lattice model

Invasion processes of pest insects in forest were elucidated through simulation by the lattice model. Population size was regarded as the state of the model, and the local rules governing movement and reproduction were accordingly incorporated with the weights for calculating the state. The constraints of population growth with the upper limit and the long distance movement contributed to rapid increase in the speed of range expansion. The spatially explicit model was feasible in integrating local development of population and provided a comprehensive illustration on the range expansion of pest populations on the lattice space. The results from the models were comparable with the field data. Advantages in the usage of the lattice model were further discussed in managing populations with high densities.