Seasonal emergence of invasive ambrosia beetles in Western Kentucky in 2017.
Xylosandrus crassiusculus (granulate ambrosia beetle, GAB) and X. germanus (black stem borer, BSB) are considered the most destructive insect pests to the nursery crop industry. This paper presents the results of a study conducted to determine the phenology of the most abundant invasive ambrosia beetles in western Kentucky, USA. Traps were deployed in Calloway, Caldwell, Graves, and Todd Counties in March 2017. The most common and numerous ambrosia species identified were GAB, BSB, Cnestus mutilatus (camphor shot borer, CSB) and Xyleborinus saxesenii (fruit-tree pinhole borer, PHFB), which are identified as invasive species. GAB and CSB were found in large numbers in western Kentucky in early spring. Ambrosia beetle attacks were identified in nursery and land scape plants. Regrettably, nothing can be done to recover infested plant, especially those that belong to a nursery. Knowing ambrosia beetle seasonal flight timing will provide valuable information to opportunely schedule preventive application of pyrethroids and thus increase the insecticide spray efficiency.