Mealybugs are key pests in nurseries producing ornamental plants. Conventional mealybug monitoring practices consist of random, visual sampling of plant material. However, mealybugs are cryptic, and many are probably missed during visual sampling. Therefore, it is difficult to determine the presence of mealybugs or their population density with this tactic. A potential alternative monitoring technique would use sticky traps baited with mealybug sex pheromones to attract adult males. Counts of adult males in these traps offer another sampling option for nursery pest managers. We will describe results of ongoing trials with simultaneous monitoring of citrus, obscure, and longtailed mealybugs in California nurseries, using traps baited with the sex pheromones of each species.