Flatheaded Poplar Borer
We found this beetle on July 31, 2010 on the side of the house.
It was very similar to this one that I posted back in May 2009, but not identical: the previous one had a stronger metallic color, a slightly differently-shaped head and pronotum (the plate just behind the head), and looks to have a different pattern of sculpturing on the face.
I think this new one is most likely the Flatheaded Poplar Borer, Dicerca tenebrica. I’m basing this partly on its appearance, but also partly on circumstantial evidence: we have a lot of poplars and aspens around the place, which is what the Flatheaded Poplar Borer eats.
The common name “Flatheaded borer” comes from the shape of the larvae, which are broadened and flattened at their head ends. They burrow under bark and into the heartwood of trees, opening them up to fungal infections, sometimes girdling and killing small trees, and occasionally weakening the wood enough that the tree snaps off.
They aren’t generally devastating to trees, though, because they have trouble getting established in vigorous, healthy trees. They are mainly an issue for trees that are drought-stressed, have damaged bark, or are otherwise weakened. They are particular problems for transplanted trees, because the transplantation process is both likely to mechanically damage their bark, and causes root damage that mimics the effects of drought stress by reducing the amount of water that the roots can take up.
Comments are closed.
That was a very striking photo at the top. Gorgeous!