Developing Management Strategies Against Invasive Ambrosia Beetles Affecting Apples and Nurseries in Kentucky

The UK-Research-Foundation (UK-RF) will evaluate and improve horticultural practices to disrupt ambrosia beetles (AB) infestations; monitor AB populations and develop management strategies to lessen AB attack to apple trees and ornamental nursery stocks; and effectively disseminate information obtained in this project. The multidisciplinary UK-RF team (horticulture and entomology) will work in cooperation with nursery and apple growers from Central, Eastern and Western Kentucky, and Dr. Ranger USDA-OHIO. The project will enhance competitiveness of nurseries and fruit trees through the reduction in tree losses and development of sustainable management practices (outcomes 4-5) (i.e.: growers adopting practices, improving their management during transplanting to reduce stress; and conduct insecticide sprays based on adult AB abundance). AB are pests of ornamental and fruit trees. Adult AB bore into the sapwood and heartwood making galleries, tunnels and a brood chamber. Then they inoculate a symbiotic fungus which contributes to tree mortality. Documented information on invasive AB attack and extent of damage to nursery or fruit trees is not available for KY. However, growers reported that AB have been killing trees and made them non-marketable in Kentucky. Surveys in W-Kentucky in 2016 detected six invasive AB species. The most abundant was granulate ambrosia beetle, black stem borer, and camphor shot borer in three western counties. These species are invaisives from Asia. Invasive AB colonize live tree tissues and they are the most destructive of the AB in nurseries. They affect trees, bushes and vines in nurseries, peaches, cherry, apples, and landscape plants.