The small cedar-bark borer is a striking beetle, with a pleasing, fuzzy pattern and endearing, long antennae. I found plenty of general information about similar beetles, but very little about this species in particular.
Beetles in the Cerambycidae family are round-head bark borers. Be advised: all of those adjectives refer to the larvae. Which makes some sense, because they spend most of their lives in that state, and the borers that bother us humans are only bothersome as larvae. Many adults are pollinators.
Depending on the species, the larvae may spend a season to several years eating the material just under the bark of a tree, in this case a sick or dying cedar or juniper. There, they grow large enough to pupate. Interesting side note: Some beetle larvae, when they’re living in a tree that’s cut for firewood or even furniture, take even longer to mature. I found one report of an adult emergence after 40 years…but I don’t know how credible that is.
Atimia confusa live up and down the west coast, and in scattered states across the southern and eastern U.S. I’ve read that adults are active in spring and fall—so this one was living up to its species name by showing up, confused, in mid-winter.
Many Cerambycidae longhorn beetles, including this one, have eyes that wrap around their antennae in a C shape. And some in the family have taken the antennae-eye interaction to an extreme. The tribe name Tetraopini translates to “four eyes.” For those beetles, the antennae completely split each compound eye into two. In Oregon, the milkweed longhorn beetle has this trait. Look for them in summer on, you guessed it, milkweed.
Here are just two of my many unanswered questions about Atimia confusa: Why is this beetle fuzzy? What advantages does the beetle family have by locating the antennae in the middle of the eyes?
See more of Karen’s work here.
Info sheet from Oregon Department of Forestry on wood boring beetles: https://www.oregon.gov/odf/Documents/forestbenefits/Woodboringbeetles.pdf. Accessed 2/1/23.
USDA on roundheaded borers: https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5343829.pdf. Accessed 2/1/23.