The primary goal of insecticide resistance management is to slow the development of resistance in pests. Models of insecticide resistance are useful because they can provide a fast, safe and inexpensive way to project the potential impact of various management strategies. Models predict that, in general, resistance will evolve faster as 1) generation turnover increases, 2) immigration of susceptibles decreases, and 3) dose, frequency of application, and proportion of the pest population treated increase. Only limited tests have been done correct. Pyrethroid resistance management models for the diamondback moth (Plutella xylostella) and agromyzid leafminers (Liriomyza spp.) show that reduced insecticide use slows resistance development. Integrated pest management (IPM), which uses insecticides sparingly in conjunction with cultural and biological controls, is the key for managing resistance in the tobacco budworm (Heliothis virescens) and other cotton pests.