Mesquite Borer with Phoretic Mites

bug identification
Location:  Central Texas
August 12, 2010 11:58 am
Could you please identify this bug. I live in central Texas. 100 degree weather right now. Was on our wood pile
Nina F

Mesquite Borer with Phoretic Mites

Hi Nina,
We wish your photos were not so blurry and that they had more detail.  This looks like a Locust Borer,
Megacyllene robiniae, and it appears to be covered with Mites.  We suspect they are Phoretic Mites and not Parasitic Mites.  Phoretic Mites are opportunistic, and they use other insects for transportation purposes.  We have never seen such a large quantity of Phoretic Mites on any insect other than a Carrion Beetle.  Was the wood in your wood pile black locust?  Knowing that would add evidence to our assumption that the beetle in your photo is a Locust Borer.

Mesquite Borer with Phoretic Mites

Update: Nina provided us with a comment that the wood pile is 90% mesquite and 10% oak, and that made a huge difference.  Her borer is a Mesquite Borer, Placosternus difficilis, which looks very similar to the Locust Borer.  BugGuide even provides a visual comparison.

2 thoughts on “Mesquite Borer with Phoretic Mites”

  1. Sorry about the blurry pictures, (only had my phone with me) he moved very fast. Our wood is 90% Mesquite and about 10% Oak. I keep checking the wood pile, but haven’t seen it again, and I now have something to try to capture it this time. Hope this little information helps.

    Reply
    • That made a huge difference. Your borer is a Mesquite Borer, Placosternus difficilis, which looks very similar to the Locust Borer. BugGuide even provides a visual comparison.

      Reply

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