The Diaprepes root weevil, Diaprepes abbreviatus L. is a devastating pest of citrus and continues to spread in Florida. Adult weevils lay eggs in masses glued between leaves in the citrus canopy. Hatching neonate larvae drop to the soil surface and burrow down to the roots to begin feeding. Larval feeding reduces yield and facilitates fungal infections by Phytophthora spp. The combination of Diaprepes and Phytophthora often kills trees and can destroy groves within a few years of an initial infestation. In developing an effective IPM program to control D. abbreviatus, it will be necessary to maximize the effectiveness of as many of the natural enemies of this insect as possible. Preliminary research indicates that some of the major mortality agents of Diaprepes eggs, larvae, and adults are predators; and that the primary predators are ants. Florida has a rich and diverse ant fauna, and ants can be extremely abundant in Florida citrus groves. With appropriate management, ants could constitute a major weapon in our fight against Diaprepes and might well be the key to controlling this insect. However, at present, it is unclear which ant species are the most effective predators of Diaprepes on the soil surface, in the canopy, and underground, and what strategies might be most effective in promoting and conserving these beneficial ant species. Previous research indicates that newly-hatched Diaprepes neonates produce an ant repellent that might severely limit the vulnerability of this life stage to ant predation. The present research tests the effectiveness of this repellent by comparing predation on neonates of different ages in a series of field assays.
Species 1: Coleoptera Curculionidae Diaprepes abbreviatus (Diaprepes root weevil, citrus root weevil)
Species 2: Hymenoptera Formicidae Solenopsis invicta (red imported fire ant)
Species 3: Hymenoptera Formicidae Pheidole moerens
Keywords: biological control
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA