Hello Bug Person,
I saw your site and thought maybe you could help me and my roommate out. We have creatures. That’s what we call them, because they are unlike anything we’ve ever seen. In the last three places we’ve lived, we have seen the Creatures in our basement. They are similar to centipedes in that they are long, have many legs, and are creepy. But that’s where the similarities end. Centipedes are flattened with legs that look like this ^ with one joint, but these Creatures have 2 joints, like spider legs. They don’t have as many as a centipede but definitely more than 8. The legs are generally the same size too, not different lengths like a house centipede. they don’t have the front "fangs" like a centipede but a mandible similar to a spider’s – no antenae no little butt feelers. And they come in 3 different colors. I’ve seen very large ones (4-5 inches), black with white spots; others were just as big but dark brown; and just the other day, in our new duplex, we found a little one maybe 2-3 inches long and light brown. They are very fast and i even hit one with a book, cutting off its lower half, and the rest of it got away. Yeah, these things are evil. Nobody knows what these things are. We’ve had hunters, floridians, Arizonians, and other self-proclaimed bug experts, but we always get the same thing: a hideous blank stare and lonely nights in our basement. Can you tell me what the creatures are?

Alex,
Be afraid. Be very afraid. Scream Alex, scream for your life. You have Tinglers living in your basement. Barring the possibility that the horrific monster from the 50’s horror flick starring Vincent Price is in your basement, following you from house to house, I can think of several additional possibilities, though none seems to exactly fit your description.
Possibility #1 is the hellgrammite, the larval form of the dobson fly. These four inch long creepy crawlies normally live in or near streams, but we have heard reports of them being found in basements. Check out this website to see if the hellgrammite is your culprit. http://www.watersheds.org/blue/nature/gallery2/
pages/hellgramite.htm
Possibility #2 would be a sun spider or wind scorpion from the family Solpugidae. They move quickly, and can be found in basements, though I haven’t heard of any American species quite as large as the creature you describe. They are closely related to other arthropods called vinegaroons.
Possibility #3 would be a different type of centipede. Scolopendra polymorpha is a six inch long species of centipede that resides within the continental U.S. You can locate a photo of it and of the sun spider on this website. http://www.angelfire.com/oh2/USInsects/
Arthropods.html
I shudder to think that we here at What’s That Bug have entered the ranks of hunters, floridians or Arizonians with blank stares, but without more concrete information, perhaps a photograph or a drawing, and some hint of your coordinates on the globe, we’ve run out of possible id’s.
Several months back, this column tried to identify a bug based on an inquiry from Deb. Here is her letter:
Hi,
I almost had a heart attack last week as I saw the biggest bug I have ever seen! I work as a therapist in an upstate New York School. My office is in the basement. As I rounded the corner to answer the phone, something huge
was slowly crawling across the doorway on the floor. It was blackish grey, about 4 inches long with a flattish body. The head looked as large as my thumbnail. It appeared to have short spikey hairs on its body, and 6 legs protruding from its middle segment. The abdomen was very large and trailed behind the legs. I didn’t notice any antennae, but it may have had pincers on the mouth. Thank God for a brave custodial worker!!! Later in the day, another co-worker said that he collected those bugs for trout bait, and that they sprout wings and fly around. Please! That was the stuff of nightmares!!!!!!!! I swear that I have seen miniscule versions of this bug in my own yard and want to know if they are the same. Could I have these prehistoric monsters flying in my back yard???!!!
—Deb

Embarassingly, I misidentified the culpret as a large roach. It turned out, in fact, to be a hellgrammite, the larval form of the dobsonfly, which you have photographed. Locally, the California Dobsonfly (Neohermes californicus) can be found near streams, generally at higher elevations, hence the frequent use of the larva as trout bait. The hellgrammites are aquatic and are found in swift streams where they prey on other insects, but they can pass dry spells under rocks and debris in the damp stream beds.
Dobsonflies are members of a primitive order of insects known as nerve-winged insects, which includes other oddities like the ant lion and lacewings. All adult nerve-winged insects, including the dobsonfly, are feeble fliers and are predaceous upon insect pests, so they are beneficial.