Tuesday, March 31, 2009
So I collected a few specimens of the beetles that were emerging from the firewood and delivered them to the Orange County Agricultural Commissioner's entomology department for positive identification. It took a few weeks, but I got the information I was hoping for: no worries about these shiny little guys and gals infesting structural wood.
These beetles are Dicerca horni, metallic wood beetles that seek out dying trees or dead wood in a tree to lay their eggs in. The larvae, known as flathead borers, tunnel under the bark eating the wood of a variety of mostly deciduous trees including alder, prunus, and others. I think typically they pupate in winter and the adults emerge in spring. My experience here in southern California has been different (adults emerging in the dead of winter) possibly due to our disturbing the logs and/or bringing them into the warm house. Anyway, these beetles do not infest dried or seasoned wood such as my house is built of. In fact the alder logs they emerge out of probably had eggs or larvae in them before the trees were felled, about 2 years ago. I am looking forward to seeing one of the larvae someday, which are more than twice the length of the adults when fully grown.