Currently viewing the category: "Gnats"
What's That Bug? does not endorse extermination

slug-like creature
Mon, Dec 29, 2008 at 3:02 PM
I found this little guy under a log at my aunt’s house in central Oklahoma this summer. I see these guys pretty often, but have no idea what they are. They leave a trail of slime like a slug, but don’t have any eye-stalks, and they make little “webs” out of their slime. Any help you can provide would be much appreciated. Thanks for the great site, and happy holidays.
Josh Kouri,
Oklahoma City , Ok.

Big Mystery


Hi Josh,
We are not certain how to classify your mystery organism. We don’t believe it is a mollusc, so would rule out that it is a slug. We also don’t believe it is an insect, though some larval insects are very uninsectlike, including many larval flies, commonly called maggots. This might be a fly larva. It also doesn’t seem very wormlike or leechlike to us. For now, we would say perhaps this is some type of fly larva, but we are far from certain. Perhaps our readership will come to our rescue. Meanwhile, is it possible for you to tell us how large this organism is?

The ones I’ve seen range in size from about 1/4 inch to one inch. The one
pictured was about 3/4 of an inch. Hope this helps. I’ll see if I have any
other pics.

Identification: December 31, 2008
Well, the description of the behavior is more helpful than the image in this case. You are quite right about it being a fly larva, most likely that of a fungus gnat in the family Mycetophilidae. Some species are known to build mucous “webs,” most notably the bioluminescent ones in Waitomo Caves in New Zealand. This one sure ‘looks’ like a slug….
Eric Eaton

January 1, 2009
I was looking at some of my older pictures today and realized that the slug-like creature is not what makes the “webs”, and the one pictured is the only one I have seen. The creatures that make the “webs” are more worm-like, and the lengths I gave you are for the worms, as I have only seen one of the slug-creatures. I still don’t know what either of the creatures is, and I hope you guys can help. Sorry for the mistakes. Thanks for the awesome site, and happy New Year.
Josh Kouri

Fungus Gnat Larvae

Fungus Gnat Larvae

Hi Josh,
Eric Eaton wrote in to say that based on your written description, your creature was a Fungus Gnat larva in the family Mycetophilidae. That would mean that your original image is still a mystery and the new photo which shows the webs would be the Fungus Gnat larva.

fungus gnat larvae update
Fri, Jan 2, 2009 at 11:31 AM
When I saw that you guys identified the “worms” as fungus gnat larvae I decided to look for better pictures on the internet.
The pictures I found looked a lot different from what I have been seeing. Is it possible the “worms” are some other type of fly or gnat larvae, or even something completely different? Thanks again for all you do.
Josh Kouri

Update: January 5, 2009
Saw the update that the image is not what is making the mucous webs. Well, I would say that the image is that of a slug, then, and it shouldn’t be that hard to ID. It is probably an introduced European species that has spread via commerce, ship’s ballast, etc.

Update:  June 2, 2017
Thanks to a comment from Rafaela, we are able to identify this as a member of the family Keroplatidae, the Predatory Fungus Gnats.  According to BugGuide:  “Larvae are predaceous or mycophagous; they spin hygroscopic webs to collect spores or small invertebrate prey. Predaceous species kill their prey with an acid fluid (mostly oxalic acid) secreted by labial glands and deposited in the droplets of their web; mycophagous larvae also have acid webs and occasionally feed on pupae of their own species or on dead insects. Larva of a Tasmanian species lives endoparasitically in land planarians.”  

What's That Bug? does not endorse extermination

pesky little bug
Hello bug people.
I have never used your site before, so I am excited to see how it works. This little bug, (that is a penny), is flying around my house. I am suspicious that it is the male of a scale insect that I am wrestling with on my plants. Does that seem possible or likely to you? Thanks.
Betsy Higgins
Florence, MA

Hi Betsy,
Our site works, if that is how you would like to refer to it, with the reception of emails. Then, depending upon our time, we try to post a few letters. We choose letters based on their content and imagery. Engaging writing always catches our attention. Interesting imagery also catches our attention. Unusual new species catch our attention and timely sightings most always get posted. We can assure you this is NOT a male Scale Insect. We believe it looks like a Dark Winged Fungus Gnat in the family Sciaridae. BugGuide has many examples and identifies only one to the genus level. Though they are annoying, they are harmless. The larvae feed on fungus and decaying organic matter. There is one image on BugGuide that illustrates both the abdominal shape and markings of the specimen in your image. We last posted a letter to our Gnat page in 2005, and that was a decisive factor in selecting your letter. More than that, we were amused that the penney in your photo is 50 years old.

What's That Bug? does not endorse extermination

All of a sudden I seem to have all of these tiny little flying things. They appear in the bathroom light and fly across the screen of my tv and computer monitor. Some days they are few and some days they seem to be everywhere. I’ve thrown out all the trash, the fruit, I have no plants. I have a dog and a cat but they do not seem to be hanging around their food or water. They’re making me crazy. I’ve attached photos of the little varmints. They look a little like flies but are much smaller.

Hi Lynn,
You have some type of Gnat. These small relatives of flies sometimes appear in great numbers for short periods of time and then just as suddenly dissappear. Some types have larvae that feed on plant roots, others on decaying organic materials.

What's That Bug? does not endorse extermination

black flying bugs
(great!) website and don’t see anything that matches what we have here – Every year about this time (Columbia, SC) we get these black flying bugs – they come in for a week or so and then go away. They don’t bite, don’t really seem to do much of anything except occasionally fly around. I think they are harmless but I’d like to know what they (or their larvae) eat so I know if my trees are in danger. It’s mostly just a little un-nerving to see hundreds of them on your wall (they seem to like the coolness of the brick) – looks kind of amityville horror-esque. I’m sending three photos – one looking down on them, one is a side view (so you can see the yellow abdomin – in this photo they almost look like lightning bugs but they definitely are not), and one is a shot of the wall – all those black spots are these bugs.
Thanks for any help you can provide.

Hi Kim,
We wanted to be sure exactly what type of gnat you are being visited by, so we checked with expert Eric Eaton. Here is what he has to say: “Ok, these are indeed gnats, dark-winged fungus gnats to be exact, family Sciaridae. I don’t know much about the outdoor varieties, but understand they can be overwhelmingly abundant at times. Adults do not bite, may not even feed at all. Eric”

What's That Bug? does not endorse extermination

swarming bugs
We live in NH. Every summer evening before sunset these bugs appear in
swarms of thousands, usually in a tight, stationary "tower" maybe 2 feet across and up to 8 feet tall. They don’t bite and can’t be chased away. If they set up a "tower" over a table, and the table is moved, they will move with the table. They never, ever sit still or land so photos are difficult, but I managed to get the attached which might help. If they’re going to share our back yard with us, we’d like to know what to call them.
John C

Hi John,
It sounds like you have Water Midges from the Family Chironomidae. The larvae develop in shallow areas of lakes, ponds and streams where there is a heavy growth of aquatic plants. Adults emerge in such numbers as to be a nuisance, but fortunately, they do not bite. According to Hogue: “Small clouds of males are frequently seen hovering in the air over or near water. At times, they form larger clouds that look like smoke over trees or tall structures; these aggregations are attractive to females and are the chief mating strategy of many species. Tremendous numbers may also gather around lights on warm summer evenings.”

What's That Bug? does not endorse extermination

Found this critter in our yard this year (we live in Texas). Sat down on the garden swing and then found we were covered in them. Have never seen one before. Sort of looks like a cross between a spider (the round torso) a fly (the wings) and a mosquito (legs and stinger like head)? Sorry I couldn’t get a closer pic. The camera wouldn’t focus on the bug and not the leafs that close. Haven’t hung around long enough to see if they sting or not.

Dear Sandra,
It is difficult to be certain with your photograph, but I’m guessing you encountered a swarm of Hessian Flies, Mayetiola destructor, an agricultural pest in the Midge family Cecidomyiidae. The maggots do serious damage to wheat plants. Adults are small (1/8 to 3/16 inch long), dark or red-tinged, gnat-like flies with long legs and antennae. The insect got its common name, according to Lutz, when the European insect was first noticed on Long Island shortly after the Hessian troops landed there. It is especially plentiful in Texas. Here is a downloaded Photo by C. Hoelscher.

What's That Bug? does not endorse extermination