A reader who has seen a rather large “worm” that bored holes in trees recently contacted us. They said that the “worm” in ½ inch in diameter, 2 inches long, has a big black head, and a creamy white body with tough skin. They said the “worm” lives in the interior of the tree. They said they at first believed it was a loggerhead worm, but that they are wrong. They didn’t send a photo, or include what type of tree they are referring to, but we will do our best to solve this mystery!
Although we can’t be 100% without a photo, we believe our reader might be seeing Roundheaded Wood Borers larvae, which are the larval form of Longhorned Beetles. There are several different species of these beetles and larvae, but they all attack dead or dying trees. The appearance and behavior of these larvae match what our reader has described, so we are pretty confident that this is a match!
Roundheaded Wood Borers deposit their eggs into the moist inner layers of bark. The larvae develop under the bark, and several species also tunnel into the tree. When larvae tunnel into trees, they can cause some significant damage. Our reader didn’t mention concern for the tree, but they should be aware that the presence of these larvae might mean the tree is dying or already dead.
To conclude, a reader wrote to us about a big “worm” with a white body and black head that was burrowing into a tree. We believe these are the larva of Roundheaded Wood Borers.