“What is this?” asks this reader about the white worm-like creatures with wide, flat heads pictured below. “I found them in a wood log.”
Fortunately for us, although no more context is provided in the submission, the picture our reader provided (for which we thank him) is so good that no more context is needed. It is clear from the photo, as well as the location in which the creatures were discovered, that these are flatheaded wood borer larvae.
Flatheaded wood borers are a species of small beetles that feed on damaged, dying and dead trees. They are also commonly referred to as metallic wood boring beetles or jewel beetles. This is because the beetle has a metallic shine to its gray body, which often comes off as a green or purple color.
Now, when it comes to the larvae, what we see in the photo is somewhat deceiving. What we might be tempted to identify as the larva’s head (the broad, flat part) is actually its thorax, while the tiny brown part at the tip of its thorax is its head. The thorax is given its flat appearance by hard plates that sit on the top and bottom of it.
Likewise, besides its flat thorax, the flatheaded wood borer also gets its name from its diet and habitat. The adult beetle will attack dying/dead trees and lay her eggs under the bark. Upon hatching, larvae will bore into the wood to feed on the rotting wood, causing significant amounts of damage over time. These critters can live for more than two years, giving them plenty of time to procreate and wreak havoc on these trees.
Given this information, it makes sense that our reader found these in a wooden log. Likewise, their presence indicates that the log is already decomposing. Now, unless this log is an item in his home, and he thinks the larvae will spread to other items and destroy them, we do not recommend acting against the beetles. He should simply leave them be.
To conclude, the white creatures our reader found inside a wooden log are flatheaded wood borer larvae. These organisms are not harmful to humans or pets, but will cause significant damage to weakened and dying trees. We hope this article proves useful, and we wish our reader the very best.