Horsefly with Orange Abdomen

2011 September 3

I found this one lying dazed at the side of the road on July 13, 2011, about halfway up the hill to home. It caught my eye partly because of its size, but mostly because of the big orange patch on its abdomen

It had probably had a close encounter with a car (which is why one wing is crooked), and never really recovered enough of its senses to fly, so there was no problem getting pictures

This is another of the horsefly species that have colorful stripes across the eyes.

It looks to me like an Orange-Banded Horsefly, Hybomitra cincta. I wasn’t too sure of this ID at first, because of the niggling little detail that all of the other specimens of this species that are on BugGuide are from New England. Which is quite a long way from here. But, it turns out that its range really does reach all the way out here, so it was just happenstance that nobody had posted one from closer to Michigan before.

At any rate, this is one that I didn’t release afterwards. Quite aside from the fact that it was so banged up that it probably wasn’t going to survive, I really don’t want to encourage horseflies around here. Their bite is quite painful, after all. So, into the freezer it went.

6 Responses
  1. September 3, 2011

    Off topic: I’ve had another armchair scientist weigh in on my spider intelligence post with some interesting anecdotes. I thought you might like to take a look.

  2. September 3, 2011

    Is that a clear chitin cover over the eyes? Looking at it, I realized that their eyes are hard, so there must be some kind of casing over them.

  3. September 4, 2011

    Yes, there is a clear cover over the eyes. Molted skins, like this cicada nymph skin, still have this cover as a crystal-clear bubble.

    I read the comment on your spider intelligence post, it certainly does sound like that spider is learning from experience.

  4. September 6, 2011


    While spending a lot of time in the yard swing, swilling beer…er…OBSERVING insects, I’ve noticed a great abundance of exceptionally large horseflies here in the Ozarks this year. As I’ve got my hands full with odonates, beetles, and lepidopterans, I really don’t care to become a Dipteran Fanatic; however, these seem to be unusually large, horribly slow, easy to swat, and in a wide variety of different species. Just say the word, and I’ll mail you a boxful.

  5. September 6, 2011

    Thanks for the offer, George, but we’ve got plenty. I have another one that I just put in the posting queue that is in the size class of the ones you are talking about – its body is a full inch long, which is monstrous for a fly.

  6. Mel permalink
    July 22, 2012

    Hi There,
    We have these horseflies in minor concentration here in ottawa, ontario Canada and in major concentration 30 minutes away in Quebec. They are larger than regular horseflies and we murder them as fast as our hands can slap. They are wicked and destroy any pleasure from swimming because they are attracted more to wet skin. The bites are easily infected which makes them even more bothersome.

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