Six species of potted nursery plants infested with Rhizoecus americanus (Hambleton) were treated with 5 chemicals by dip, drench, foliar spray, and granular application to determine effective safe materials and the best method of application. Dip, drench, and granular treatments were superior to foliar sprays in reducing the population of mealybugs. Dimethoate, phorate, and methomyl were effective but phytotoxic to most species. Monocrotophos was effective and least phytotoxic.