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

Subject:  Weird worm like creature found in water
Geographic location of the bug:  Petersburg, Tennessee
Date: 04/29/2019
Time: 09:20 PM EDT
Your letter to the bugman:  I was going outside catching tadpoles to grow and I can across this worm like thing. I scooped him up and put him in with the tadpoles. Maybe he wasn’t originally in the water and he fell in? But I didn’t want to take the chance. I’ve looked up tons of worm like creatures and even asked my parents to no avail. It would be appreciated greatly if you could help figure this mystery out. Thanks in advance.
How you want your letter signed:  Sierra

Horse Fly Larva

Dear Sierra,
We believe this is a Horse Fly larva.  According to Quora:  “
Most horse flies are associated with water, and the carnivorous larvae can be found therein. I have collected black horse fly larvae while searching through the muck and mud at pond edges. [T]Here’s a Colorado State University photo by Jennifer Bonnell of what is probably a black horse fly larva eating a small frog; they’ll also eat other insects, and, while I’ve never seen it, I’m sure they’ll eat any weakened or trapped minnows they might be able to.  Through the summer, the larvae grow in the water through 6–9 instars, and ultimately spend the winter in the the mud in their last instar. In spring, still in the muck and mire, they pupate and a few weeks later, the adults emerge.”  You might not want to keep this predatory Horse Fly larva with your tadpoles.

What's That Bug? does not endorse extermination

Subject:  Frozen Like Han Solo
Geographic location of the bug:  a pond in northern IL
Date: 12/10/2018
Time: 11:07 PM EDT
Your letter to the bugman:  Hi.  We were hiking in the woods and saw a few of these trapped in the ice of two different shallow ponds near our home.  Each specimen was about 2 to 2.5 inches long.  I thought it must be a larvae of a pond insect, but I haven’t been able to find any that are supposed to be that big.  Any ideas?
How you want your letter signed:  Mary

Horse Fly Larva

Dear Mary,
This looks to us like the larva of a Horse Fly.  There is a matching image on Quora where it states:  “Most horse flies are associated with water, and the carnivorous larvae can be found therein.”

Thank you! and Yuck!
I appreciate your help.  I always attempt to do my own identifying, but whenever I am stuck, you always come through.
My curiosity thanks you.
Mary
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