Kaolin clay application as a deterrent for ambrosia beetle (Curculionidae: Scolytinae) attack at ornamental nurseries

Exotic invasive ambrosia beetles have been listed as the third-worst arthropod pest for nursery production in the southeast U. S.  Controls centered around insecticides need to be well-timed with beetle dispersal into the nursery, with repeated applications often necessary to cover the long dispersal period.  Adding the potential gustatory/visual deterrents provided by kaolin clay to standard chemical control measures may yield a synergistic effect that protects valuable trees, limits non-target effects on beneficial organisms, and prevents the development of resistance or secondary pest outbreaks.  We present here preliminary data from the first field trials of four treatments in both South Mississippi and East Tennessee: kaolin, bifenthrin, a tank-mix combination of the two, and a blank control.  While not significantly different, kaolin-treated trees had nearly 50% fewer beetle galleries as compared with controls.