Exotic ambrosia beetles are costly pests of ornamental and fruit trees nationwide, from front-yard plantings of Japanese maple and oak to commercially grown orchards of cherry, peach, plum and even avocado.
Now, however, Agricultural Research Service (ARS) scientists may have found a way to turn the tables on the beetles. Unchecked, the two- to three-millimeter long pests tunnel into the sapwood of host trees and expose them to symbiotic fungi that obstruct the flow of nutrients.
The researchers' tactic exploits a key weakness of ambrosia beetles – namely, their attraction to ethanol emitted by stressed, injured or dying trees and a reliance on the alcohol to "farm" gardens of the fungi as food without interference from other competing microbes.
Trees severely infested by the beetle-fungus duo cannot be saved, so careful monitoring and preemptive measures must be taken beforehand. These include deploying ethanol-baited traps to monitor the beetles' flight and timing insecticide treatments to deter them from boring into the trees on which they land. However, the traps also tend to capture non-target beetle species, obscuring accurate counts and monitoring.
This article is originally written by Jan Suszkiw with the U.S. Department of Agriculture. For the whole story, click here.