Monitoring the susceptibility of an insect pest population both geographically and temporally is a key component of a resistance management program designed to preserve the efficacy of a crop protection product or crop trait. Methods and considerations for the statistical design of the monitoring bioassay are presented with particular emphasis on two-dose monitoring assays. Simple statistical methods to visualize geographic and temporal trends will also be presented. The goals of the methods are to highlight and communicate shifts in susceptibility before significant tolerance develops so that remedial actions can be applied in a timely fashion.