In an attempt to determine what strategies of resistant germ plasm deployment would most successfully inhibit Hessian fly,Mayetiola destructor(Say), adaptation to wheat resistance factors while offering significant crop protection, a computer simulation model was developed to mimic ecological/genetic interactions between Hessian fly populations and resistant winter wheat. Durability of the following resistant germ plasm deployment strategies was examined: 1) sequential release of two pure cultivars, each with a single resistance factor, 2) release of a random spatial mixture of these two cultivars, 3) release of a pure cultivar in which both resistance factors were present in each plant (pyramided), and 4) modification of each of the above deployment strategies by addition of totally susceptible wheat to the system. Effects of temporal and spatial characteristics of the mixtures were also explored. Interpolating a pyramided resistant cultivar with some totally susceptible plants offers the highest relative durability in most cases, and is predicted to last>400 fly generations under some conditions.