Currently viewing the category: "Horse Flies and Deer Flies"
What's That Bug? does not endorse extermination

Subject:  Large fly like bug
Geographic location of the bug:  Ontario, Canada
Date: 08/08/2018
Time: 10:08 PM EDT
Your letter to the bugman:  Hello! What’s this bug? It was on the wall outside my store …It’s horrifying and I must know if it is a horsefly or cicada or another insect I haven’t thought of..
How you want your letter signed:  Sparkledemon

Horse Fly

Dear Sparkledemon,
This is definitely a Horse Fly and it looks to us like
Tabanus marginalus pictured on BugGuide, and it is very curious that though BugGuide states: “The most common biting horse fly throughout the world” there are only three images posted there and all are from a limited area in the Northeastern portion of North America, including Ontario.

What's That Bug? does not endorse extermination

Subject:  Huge Fly?
Geographic location of the bug:  Dubuque, Iowa
Date: 08/02/2018
Time: 10:26 AM EDT
Your letter to the bugman:  What is this thing – I’ve never encountered one of these before…  An inch or more in length!
How you want your letter signed:  Rich

Female Black Horse Fly

Dear Rich,
Thanks so much for providing such excellent images of a female Black Horse Fly,
Tabanus atratusMale Horse Flies have much bigger eyes and only females bite.

Female Black Horse Fly

Female Black Horse Fly

 

What's That Bug? does not endorse extermination

Subject:  Is this a deer fly?
Geographic location of the bug:  Elicott City, MD
Date: 07/31/2018
Time: 10:34 AM EDT
Your letter to the bugman:  A friend of mine spotted this little B@#$%^d on his car.   I sort of remember this as a deer fly from my childhood in the northern midwest, but never saw one on the east coast.  If I remember correctly, a bite from these guys will raise a respectable welt.
He said it was HUGE for a fly, maybe 3/4 inch?
Thanks for the help.
How you want your letter signed:  Ray Oberg

Female Black Horse Fly

Dear Ray,
This is a Black Horse Fly, not a Deer Fly, but Horse Flies and Deer Flies are both in the family Tabanidae, so they do resemble one another.  Deer Flies and Horse Flies are both biting Flies, but only the females bite and suck blood, and the bite is reported to be quite painful.  This is a spectacular image of a female Black Horse Fly,
Tabanus atratus.

What's That Bug? does not endorse extermination

Subject:  Beauty and a beast
Geographic location of the bug:  Nova Scotia, Canada
Date: 07/19/2018
Time: 05:41 AM EDT
Your letter to the bugman:  Hi Bugman!
I was recently working on stream habitat assessments …  On another day, we were looking at rocks for freshwater benthic macroinvertaebrates and I found this worm-like creature that was not on our super-simplified ID guide. It was translucent and you could see everything shifting around when it moved. As I was trying to take photos and video of it moving/wriggling, it bit me (or stung/poked me), drawing blood and I dropped it. Luckily (or unluckily depending on how you look at it, I suppose), we came across another one later. As I watched it move this time, I believe what I might have gotten stuck with its back end grippers which it seems to use to grip onto the rock face. I was looking at some other aquatic larval stages for different insects and cam across an image of crane fly larvae that looks similar, but again, I’m not really sure and was hoping you might have a better idea.
Here’s hoping!
How you want your letter signed:  Many thanks, Van

Horse Fly Larva

Hi Van,
We believe your guess that this is a Crane Fly larva is incorrect, but we do believe you have the insect order correct.  We believe this is an aquatic Horse Fly larva and according to the Missouri Department of Conservation:  “The larvae of horse and deer flies are fairly straight, segmented, wormlike maggots that are tan, whitish, or brownish. Several fleshy rings circle the body. They are robust, circular in cross-section, and taper at both ends. There are no true legs, although fleshy, nobby pseudopods or prolegs are present. In relaxed specimens, a thin, pointed breathing tube extends from the hind end to protrude above the water surface.”  BugGuide has an account of a person being bitten by a Horse Fly larva.

Horse Fly Larva

Thanks Daniel!
Go figure, the horse flies are still jerks even before they grow up 😀
Thanks for the help.
Van
What's That Bug? does not endorse extermination

Subject:  What’s this big black fly with yellow middle?
Geographic location of the bug:  Tweed River, Pittsfield VT
Date: 07/17/2018
Time: 02:07 PM EDT
Your letter to the bugman:  Please help us identify this enormous fly or whatever the heck it is!! We took the kids and dog for a swim in the River at the end of a hot day and these flies were relentless! We’ve never seen them before and I can’t find anything similar on the internet. If anyone knows what this is, it’s you.
How you want your letter signed:  Thank you!

It’s an orange banded horse fly! I posted to Facebook and a friend helped us identify. So no need to waste your time on us. Horse fly?? I feel kinda silly I even asked!! LOL.
Thank you!
Michelle D.

Orange Banded Horse Fly

Dear Michelle,
After verifying the identity of this Orange Banded Horse Fly,
Hybomitra cincta, on BugGuide, our first thought is that it is a stunningly beautiful Horse Fly and BugGuide does note:  “Females have first three segments of abdomen orange, rest of abdomen black (sharply delimited), and wings dark. Males are harder to identify.”  Don’t underestimate the amazing diversity of Horse Flies.  Some especially striking examples from our site are the only green North American Horse Fly Chlorotabanus crepuscularis, the American Horse Fly and the Western Horse Fly.

What's That Bug? does not endorse extermination

Subject:  Large Fly
Geographic location of the bug:  Michigan
Date: 07/15/2018
Time: 09:23 AM EDT
Your letter to the bugman:  I saw this fly sitting on my trash can. Hot weather. The ledge he is sitting on is about 1 1/4″ wide. I can’t find any Google images that match. Can you identify this bug?
How you want your letter signed:  Tom

Horse Fly: Tabanus stygius

Dear Tom,
This is an impressive female Horse Fly and we believe we have correctly identified her as
Tabanus stygius thanks to this BugGuide image.

Horse Fly: Tabanus stygius

Thank you for your response and identifying the fly. I’m impressed you replied so quickly.  Thank you.

You happened to send your request during the window of time in the morning we try to devote to responding.

What's That Bug? does not endorse extermination