SPBLOB is a computer simulation model for the interaction between loblolly pine (Pinus taeda L.), the economically most important forest crop in the United States, and the southern pine beetle (SPB: Dendroctonus frontalis Zimm.), the major insect pest for this species. The model simulates loblolly pine stands from time of planting until harvest. It mimics day-to-day changes in SPB populations, and the associated tree mortality caused by these bark beetles. In addition, it provides yearly updates of tree mortality due to competition and of growth for the surviving trees. Chiefly, the model and its simulation codes are designed to function as research tools for investigating the influence of stand properties on SPB activities, and of the reciprocal impact of beetles on tree mortality.