The pea leaf weevil, Sitona lineatus (L.), (PLW) has been a serious pest of pea, Pisum sativum L., in northern Idaho and eastern Washington since the early 1970’s. Recent surveys have shown that abundance of the PLW and the amount of PLW injury are lower in peas grown using no-tillage (NT) methods, in which the seed is planted directly through the prior year’s stubble, than in peas grown using conventional tillage (CT). This study tested a potential mechanism producing this pattern by comparing immigration and colonization by the pea leaf weevil in CT and NT peas in northern Idaho in the spring and summer of 2005. Bi-directional flight interception traps and bi-directional pitfall traps were used to monitor relative abundance of PLW and relative movement rates into and out of NT and CT plots in a replicated trial at the University of Idaho’s Kambitsch farm, near Genesee, Idaho. Fixed area linear soil samples were taken after peak immigration to measure absolute PLW densities. Plant stand and PLW injury were monitored weekly. This study has been developed in an attempt to better understand pre-ovipositional flight patterns and subsequent colonization of the PLW into two different tillage systems in northern Idaho. Results will be presented upon completion of the 2005 summer field season.