wood boring beetles
Location: Central Maryland, US
December 7, 2010 12:04 pm
What’s this bug?? A huge colony of them had eaten a large part of a red oak in Maryland, and killed the tree.
These are not beetles, but True Bugs. We are quite certain that they are Flat Bugs in the family Aradidae, and your image is the first in the category of Flat Bugs on our site. According to BugGuide, they are: “Oval and very flat bugs found under or on bark. Abdomen extends beyond wings. Antennae and beak have four segments. Lack ocelli” and that they are found “mostly under bark, on fallen logs & tree limbs, bracket fungi.” BugGuide elaborates by indicating they feed upon “mycelia or fruiting bodies of wood-rotting fungi” and “many bark-dwelling spp. are greagrious”, though there is no indication that they are injurious to trees. We suspect the tree was in poor health for some other reason and that it was riddled with fungi, and that provided a likely habitat for a robust population of Flat Bugs.