Adult Colorado potato beetles, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), released uniformly at densities of 2, 8, 16, and 32 beetles per plant, had an emigration rate independent of initial density per plant. The overwintered (postdiapause) and summer (prediapause) adult beetles emigrated at overall mean rates of 0.403 and 0.398 beetles over the first 4 h after release. The reduction in the mean percentage of released overwintered and summer beetles per plant over a period of 124 h after the initiation of the release followed an exponential decay model. Over that period, the emigration rate of overwintered populations changed faster than that of summer populations. The corresponding immigration rates into beetle-free areas (342.8 m²), which surrounded the RAs (37.4 m²) of the potato plots, were low. The overwintered and summer adult beetles immigrated at overall mean rates of 0.09 and 0.07 beetles over the first 4 h after release. A capture-mark-release-recapture test carried out using the eight beetles per plant density in 1998 showed that cross-contamination of the release plots was not a factor in the study.