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Stinging larvae? - Tabanus punctifer

Stinging larvae? - Tabanus punctifer
Shoshone Basin, Twin Falls County, Idaho, USA
March 27, 2005
Size: 22 mm
This critter bit/stung/hurt me in a remote hot springs. I assume it fell into the water. The motion is a slow telescoping-accordian movement that's visible through the transparent outer shell between the dark bands.
The sting was much like a hornet or yellowjacket. Intense burning and itching with reddened swelling for about 18 hours.

We found one in Krul Lake
We found one in Krul Lake where I take my kids swimming in Black Water River State Forest, Northwest Florida. Got some really good close up pictures of it and a video of how it moves but can't figure out how to upload it.

Stinging maggot - which is the first search I tried
I found this larvae in a window box thinggy i made in northeastern Ohio in a puddle of water (that was there only a day or two), so i thaught it was a big maggot, cuz they are very similar looking. As i picked it up it stung me. It does hurt. And it itched for about two or three days, much longer than the 18 hours it states above, maybe because of the sensitive spot it got me (right ring finger right where it meats with the middle finger). There is still redness 5 days later and a small white bump. No biggie. I threw it back into the water as punishment, thinking it would drown... joke is on me i guess :)

This is a larva of Tabanus pu
This is a larva of Tabanus punctifer Osten Sacken. Larvae are found in a wide variety of aquatic habitats, including warm mineral springs and I have collected them from livestock watering tanks that overflow and irrigation ditches throughout Arizona. The larvae of this species are extremely aggressive and when handled carelessly, they can draw blood. There is even a record of them feeding on small spadefoot toads in Arizona by Tom Eisner.

Tabanus punctifer Osten Sacken
I'd love to see a picture of the adult fly to see if it's native here.
This past May the small desert creek next to this hotsprings flooded in a big way. MANY of these larvae were seen in the slack water still alive but being flushed out of the creek banks by the thousands. Maybe as a result the summer was almost totally biting fly free. Some Deer Flies and a few BIG black horseflies with cream-colored eyes, but the fly problem was not at all bad. There is usually a six week period in June and July where outdoor activities are impossible for six to eight hours a day.

Tabanus punctifer does occur
Tabanus punctifer does occur in Idaho, although it may not be very common. There are images of both male and female on the bugguide site.

Tabanids of Idaho
There is an excellent publication for your State: Nowierski, R.M. & A.R. Gittins. 1976. The Horse Flies and Deer Flies of Idaho. Res. Bull. #96, 48pp. Univ. of Idaho, Agric. Science Building, Moscow, Idaho.

Horse Fly Larva - Tabanus sp.
These larvae are aquatic. They have mouthparts that are identical to those of rattlesnakes in structure. A pair of hollow fangs that are connected to a poison/anaesthecic salivary gland further back in the body. These mandibles can easily break through human skin and inject the immobilizing contents of the salivary glands. Normally used to paralyse, and perhaps digest, prey. They are capable of quickly immobilizing/killing animals as large as frogs. They are strictly carnivores and eat 'meat'.
So as you guessed, you were bitten but it does feel like a wasp sting. A subtle difference. Either way I know it hurts; as a student of tabanids I have been bitten many times; it makes handling these a hazardous occupation!
Very nice photo.

Thank you very much!
I'm still puzzled as to 'where' it came from. The concrete soaking pit stays about 105 deg and there is no cooler water up hill from it, but a creek just below. Is it possible this larvae 'traveled' from one body and fell into the other? After scooping the offending varmint out of the tub I watched it travel about three feet on wet concrete, but it was slow going.

There is one thing for certain--I'll be checking my soaking spot for things that go BITE in the dark from now on.
Horse flies and deer flies are a terrible pest around here for about six weeks of early summer.

Aquatic in a scientific sense
These bugs are air breathing and live in saturated soil or muck, they are constantly wet and therefore live in at least a film of water. Some of them can live in the mud at the bottom of ponds where they can actually "tap into" the vessels of aquatic plants to get oxygen. Some species live under rocks in rivers and thus must be able to extract oxygen from the water.
They pupate on 'dry' land close to the water. Your beast may have been moving from the stream seeking a place to pupate and inadvertenly ended up in the pool.
Would love to see some photos of the adults you get there in early summer for incorporation into the Tabanid guides here in BugGuide.

Tabanids at hot springs.
I recall seeing larvae like these in hot springs in the Alvord Desert of southeast Oregon, so I think they can at least tolerate these conditions, if not thrive in them. There were adult T. punctifer present as well (a Memorial Day weekend).

Photos will be forthcoming---

Thanks again. I'll be happy to photo the several different horse flies that plague the area for you. I wish I had photo capability for my stereo microscope...that would be something!
The habitat you describe is plentiful here....muck and wet ground in the middle of the high desert. I'll be on the look out for more of them and post photos.

Strat larva?
It has the makings of an aquatic soldier fly larva of the subfamily Stratiomyiinae. These are scanvengers/grazers and may have strong mouthparts for scraping food from the surface of submerged structures. I can imagine that if they let loose the scrapers on tender human skin that it may feel like a sting.


Tabanus punctifer larvae
This looks like a Tabanus punctifer larvae aka Horse Fly larvae. They have sickle shaped mandibles which are hollow and connected to venom glands inside the body which is used to subdue prey. They are voracious carnivores and the bite from one of these is quite painful and is due to envenomation. I mistakenly noticed one of these larvae in a pool of water off of a creek I was fishing in and mistakenly picked it up thinking it was something like a caddis fly or like nymph/larvae? The bite felt like a sting from a bee or hornet, the puncture marks from the wicked looking hollow mandibles were clearly visible and then it swelled up initially after the bite, then developed what looked like a blanched area, like a white blister then subsided within a couple days afterwards, though it itched like mad for a while. If you see one in the water or whatnot don't pick it up with your bare hand or you may receive a painful surprise! Definitely not a scraper type bite with this critter, rather like two 'stingers' going into your skin!

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