Thousandcankersmontage

Counterclockwise from top are black walnut tree, black walnut leaves, walnut twig beetle

The black walnut tree is threatened by the walnut twig beetle.
Tree and leaf photo by Robert Vidéki, Doronicum Kft., Bugwood.org. Walnut twig beetle photo by Steven Valley, Oregon Department of Agriculture, Bugwood.org | Forestryimages.org