What's That Bug? does not endorse extermination

Subject: Giant True Fly
Location: Tortuguero, Costa Rica
May 21, 2013 2:31 pm
Hi Bugman,
I live in the coastal rainforest of Costa Rica and find all kinds of large and interesting bugs on a regular basis, but this was pretty impressive. I’m guessing she’s a female because there appears to be an ovipositor, but I don’t know much about Diptera. Hoping you can help!
Signature: Jennifer

Horse Fly

Timber Fly

Hi Jennifer,
WOW, that is some big Horse Fly in the family Tabanidae.  In addition to the ovipositor, you can tell she is a female because of the spacing between her eyes.  Male Horse Flies have no spacing between the eyes.  You Horse Fly looks somewhat similar to the mounted image of
Myiotabanus muscoideus pictured on Sciency Thoughts, and that species is found from Mexico and Guatemala according to the site.  We have not been able to locate anything definite regarding the identification of your distinctly large Horse Fly, but perhaps one of our readers will have better luck.

Horse Fly

Timber Fly

Update:  January 21, 2014
Thanks to a comment from James, we now know that this is a Giant Wood Fly or Timber Fly in the family Pantophthalmidae, genus
Pantophthalmus.  We located a matching photo on P-Base and on Panama Silvestre.

What's That Bug? does not endorse extermination
Location: Tortuguero, Costa Rica

4 Responses to Timber Fly from Costa Rica

  1. This is not actually a horsefly, Tabanidae; it is a Giant Wood Fly, Pantophthalmus sp., family Pantophthalmidae.

  2. This is not a horsefly, Tabanidae – it is a Giant Wood Fly or ‘timber fly’, family Pantophthalmidae, genus Pantophthalmus.

    I commented on this yesterday, but my remarks were somehow deleted.

    All the best,


    • bugman says:

      Hi James,
      We have been out of the office and just returned. We will try to locate a link online and update the posting.

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