Hardwood Stump Borer

Subject: Big Beetle!
Location: Austin, Texas
July 18, 2013 6:31 am
Dear Bugman,
I’m from Austin, Texas and found this big beetle inside our apartment when we returned home from vacation. So I strategically picked it up and released it outside thinking I’d never see it again. Well, the next day there it was lurlurking around the entrance of the apartment. It’s been raining a couple of days so I figured maybe the rain washed it from its habitat. Can you tell me why type of beetle this is and is it harmful? Thanks in advance for your help.
Signature: Concerned Texan

Hardwood Stump Borer
Hardwood Stump Borer

Dear Concerned Texan,
“Harmful” and “harmless” are really such relative terms since even the most benign creatures can cause harm in certain situations.  This is a Hardwood Stump Borer,
Mallodon dasystomus, and it is not an aggressive species, but those mandibles which can chew through wood can most likely draw blood from anyone foolish enough to carelessly handle it.  According to BugGuide:  “Larvae bore in live heartwood of trees, incl. oak, elm, willow, pecan, maple, sycamore, etc.” and “take 3-4 years to mature. Can be economically damaging. Adults attracted to UV lights.”  Adult Hardwood Stump Borers will not damage your home nor its furnishings.  Larvae might be found in recently dead stumps.  We suspect this individual was attracted to lights and that is the reason you found it in your apartment.

Thanks Bugman! I tried to Google this beetle and was I was overloaded with web searches. I happen to stumble upon your website and I am pleased that I did!
Thanks again.
Concerned Texan

2 thoughts on “Hardwood Stump Borer”

  1. I found a whole nest of these swarming through some dead tree trunks in my backyard earlier this year…unfortunately found a couple roaming near the fireplace too after I’d brought some wood in for the fire.

  2. Big 2.5″ one of these lurking around my front stoop tonight in northwest Georgia. Have never seen such a mean looking bug…had to look it up. Thank you for helping us identify it.


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