Hibiscus mealybug, Nipaecoccus viridis (Newstead) and mechanically induced citrus volatiles

Insect herbivores use plant volatile organic compounds (VOCs) to locate suitable hosts for foraging and oviposition. Citrus plants produce VOCs. Hibiscus mealybug, Nipaecoccus viridis (Newstead), is a recent invasive pest of citrus in Florida. Large aggregations of mealybugs at points of injury to citrus tissues were observed during the rearing of N. viridis. Therefore, we compared captures of N. viridis in cardboard traps near branches that were mechanically damaged versus those left undamaged, which confirmed that N. viridis were attracted to damaged tissues of citrus. Based on this observation, I hypothesized that VOCs specifically induced by the damage were the source of attractant to the mealybugs. The objectives of this study are to describe and compare the profile of VOC emissions from mechanically damaged versus undamaged citrus branches, and to describe the behavioral responses of N. viridis to mechanically induced VOC emissions. We found qualitative and quantitative differences in the profile of VOC emissions collected from mechanically damaged and undamaged citrus branches. Varying responses were also observed when hibiscus mealybug nymphs are exposed to mechanically induced volatiles.