Pink bollworm (PBW), Pectinophora gossypiella (Saunders) remains a significant economic pest of cotton in the southwestern US. This project aims to determine the extent that PBW can invade and establish economic infestations in cotton producing areas within the southeastern US. In the first phase of the risk assessment, we identify regions where survival and reproduction of PBW are most likely. Three analyses based on the climate matching software CLIMEX indicate that the probability of establishment is >50% in portions of almost every cotton producing state in the southeastern US. Cold temperatures reduce the chance of establishment in more northern states, and excessive soil moisture limits chances in parts of the Southeast. In the second phase of the risk assessment, we determine the severity of infestations in high risk areas with the process-oriented computer simulation PBWSIM. PBWSIM models the dynamics of pink bollworm populations in response to temperature, crop phenology, and insecticide applications. Analyses based on weather data for the southeastern US are in progress.