Scientific name: Plectrodera scalator (Fabricius)
Facts: Cottonwood borers are robust and large with the adults about 1 1/4 inch long. The long antennae make the appear even larger. They are black and white in color and there is a lot of variation in the coloration with some specimens almost entirely black.
The larvae are wood borers that feed in cottonwood and willow. They generally infest trees that are weak or dying but sometimes attack trees that are quite healthy. Adults also feed on the same trees and can sometimes be found in good numbers near the base of a tree.