Controlling Borers in Southeastern Peach Orchards
Entomologist Ted Cottrell, with the Southeastern Fruit and Tree Nut Research Lab in Byron, GA, does research on peach trees, focusing on pests attacking them. His research provides pest management solutions for growers so they can continue to economically provide peaches to consumers.
Two species of borers attack Southeastern peaches: lesser peachtree borer, which attacks the cambium (living tissue under the bark) on aboveground portions of the tree; and peachtree borer, which attacks the cambium of roots. Larvae of these species kill young trees when they feed on growing tissue, and they severely reduce fruit production when they eat older trees. The technique he and his colleagues developed to attack these serious pests of the Southeast is mating disruption.
Mating disruption is a pest management technique which prevents males from finding females, thus preventing mating. Prior attempts using mating disruption were not done on a scale large enough to overcome the pests’ dispersal capability. When the areawide concept was used and all peach orchards in a 20 square mile area were treated, mating disruption leading to pest control was achieved.
A key to success in their use of mating disruption was the development of a pheromone dispenser lasting all season. This dispenser is wrapped around a tree limb and constantly releases a synthetic female sex pheromone. A long-lasting dispenser was needed to match the nine-month window (March thru November) of pest activity across the southeast. Manual application of 150 dispensers per acre provides pheromone coverage of the orchard. The synthetic pheromone prevents adult males from detecting pheromone emitting from females.
To determine if their technique worked, the scientists put pheromone-baited sticky traps (mimicking pheromone-emitting females) on tree branches in orchards. If males were not attracted to the sticky traps (not captured in trap), then the scientists knew the dispensers were releasing a sufficient amount of pheromone. They found that the pheromone in the dispenser prevented males from finding the scent in the sticky trap all season long. More importantly, they documented a reduction of pest reproduction in the treated peach orchards. Mating disruption has now been used on > 5,000 acres of peaches in Georgia. — By Peggy Greb, ARS Office of Communications.