According to Angel Acebes-Doria, pecan entomologist with University of Georgia Cooperative Extension, ambrosia beetles are damaging south Georgia pecan orchards. Ambrosia beetles are not confined to pecans, though. They can damage many ornamental trees and shrubs, as well. Ambrosia beetles attack plants that are undergoing stress. You can discover ambrosia beetle infestions by the toothpick-size tunnels protruding from plant bark, and from the "sawdust" powder that collects at the base of the infected plant. Info in this article is worthwhile for home gardeners to know.