Not available – first paragraph follows: Development of insecticide resistance of the leafminer, Liriomyza trifolii (Burgess), in chrysanthemum and gerbera greenhouses throughout California has resulted in serious damage. It has been estimated, for example, that California's chrysanthemum industry lost $17 million in 1981. With eventual registration of new insecticides, this “leaf-miner crisis” should be considerably reduced, but the new materials cannot be viewed as long-term solutions to the problem. Growers must strive to maximize the effective field life of these new compounds by using them only when they are needed. In addition, until these new insecticides gain registration, growers must maximize the efficacy of existing compounds.

This research was supported by SAFE Endowment.