Flat-Headed Borer is the common name of Chalcophora virginiensis. The insect extendsd its flattened burrows deep into the wood of the tree. The larvae grow to the length of two inches.
GalleriesOther Orders of Insects
L. H. Bailey Standard Cyclopedia of Horticulture (New York, New York: The MacMillan Company, 1917) volume 1, page 367