Evaluation of management practices for pink hibiscus mealybug under semi-field conditions

The pink hibiscus mealybug, Maconellicoccus hirsutus (Green), is a highly polyphagous pest and recent introduction to the southern USA. The effectiveness of management practices are not well established and their relationship with males captured in sex pheromone traps is unknown. Potted hibiscus that were heavily infested with mealybugs were held individually in screened cages and treated with insecticide, parasitoids, predators or mating disruption or left untreated. At weekly intervals for 7 wks, the production of dispersing nymphs and the capture of males in pheromone traps were recorded. At the end of the study, the population of mealybugs on each plant was assessed. The mean total number of nymphs dispersing from plants treated with mating disruption and parasitoids did not differ significantly from the number captured on untreated plants, while significantly fewer were captured on plants treated with predators or insecticide. Significantly more males were captured in pheromone traps deployed with the untreated, parasitoid, and mating disruption treatments than with the predator or insecticide treatments. After seven weeks, the size of populations varied by treatment, with untreated and mating disruption showing significantly more nymphs than parasitoid, predator or insecticide treatments. The relationship between males captured in pheromone traps and population density was not consistent when management practices varied.