3: Phenology and diversity of ambrosia beetles in woody nurseries, pecan and tree fruit orchards in Georgia

Ambrosia beetles are serious wood-boring pests of woody nurseries and pecan orchards negatively affecting production in Georgia. These beetles threaten the tree fruit industry in the state. Some of the affected ornamental trees are dogwood, flowering cherry, redbud and magnolia. Young trees that have been exposed to stress factors such as water logging and freezing winter temperatures are attractive to these beetles. They bore into heart wood of the tree and create galleries which can cause branch dieback and tree mortality. Because there is limited knowledge on temporal incidence of beetle attack and diversity of beetle species in Georgia, the objectives of the study were to determine the phenology and species diversity of ambrosia beetles in production areas. In 2018 and 2019, we deployed monitoring bottle-alcohol lure traps in woody nursery, pecan and tree fruit orchards. Six traps were deployed per site and at least three sites were selected per production system. Weekly trap captures from various agro-systems show that granulate ambrosia beetle (Xylosandrus crassiusculus) is the most common species on ornamental and pecan trees. Results also show that peak granulate ambrosia captures varied by production system. Ornamental nurseries in middle GA had peak capture to occur early April to mid-May, while in the pecan orchards in south GA showed peak capture to be late February to mid-March and again in April to mid-May. The data obtained from this study confirmed the need for ambrosia beetle monitoring in tree production systems to precisely time management decisions.