Cedar Tree Borer

Subject: new bug
Location: Bend Oregon
February 21, 2015 11:47 pm
this is a new bug all over my house we were on vacations to Thailand for 2 weeks and the day I got back I notice this bug all over the house, is not in the rooms just in the kitchen and the living room! but in the last two hours I saw 5 of them… please help me
Signature: Marian

Cedar Tree Borer

Hi Marian,
We are requesting assistance from Eric Eaton to help identify your beetle.

Hi Eric,
It looks a bit like a checkered beetle, but the person from Bend Oregon who sent the picture has indicated that significant numbers are appearing inside the home, which makes me wonder if it is a wood borer.

Eric Eaton provides identification:  Cedar Borer
It is indeed a longhorned woodborer, the Cedar Tree Borer, Semanotus ligneus.  Here’s the Bugguide link:
Yes, they are likely emerging from firewood, but potentially from the structure itself, or cedar furniture.  For reasons still unclear, when a beetle larva is trapped inside milled lumber, it frequently extends the life cycle of the larva by years, sometimes decades.  Then, suddenly, beetles are popping out of whatever the lumber was used to build.
Eric Eaton

Hi Again Marian,
Eric Eaton has identified your Cedar Tree Borer, and Bugguide indicates it feeds on “Juniper, Cedar”
in the larval stage.  Since you found significant numbers in the home, we are speculating that wood that was infested with larvae resulted in a mass eclosion or emergence.  Perhaps there was some firewood in the home, or perhaps you bought a recent piece of cedar or juniper furniture made with infested wood.

Daniel and Eric thank you so much! yes there was so firewood (juniper) inside.
Thank you again !

1 thought on “Cedar Tree Borer”

  1. Do these bugs pose any problems or dangers, other than just being pests. I have had an influx of them in the past few days and we also use juniper firewood.


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