Crane Fly Pupa, and a Medley of Possible Adult Forms

2011 April 9

Sandy and Sam were putting in a flower bed at the east end of the house at the end of the summer [1], and while digging it out they found this large, spiky thing. It was about an inch long, and pretty active, crawling along quite briskly and acting for all the world like a larva of some sort.

I’d heard that crane fly larvae were these big, leathery, legless maggoty things, and figured that this was probably one of them. But, on inspection, we couldn’t figure out which end was the head end – there didn’t seem to be any openings at the tapered, spiky end;

and the large, blunt end not only didn’t have any openings, but appeared to have a couple of antennae (which is weird on a maggot)

Checking around on BugGuide, I saw that it didn’t really look like the crane fly larvae – they aren’t generally spiky like that. But, it turns out that it did look like a Crane Fly Pupa. Its high level of activity had fooled me. I expect pupae to just lie there and maybe wiggle, not actually crawl across the table like this one was doing.

There are two big problems in identifying this pupa further: first, all the Tipula pupae evidently look the same; and second, Crane Flies are the largest family of flies,, and even just the Tipula genus (which this pupa appears to be in) evidently has 473 species listed for North America. So, this could have been the pupa of one of these:

Or one of these:

Or one of these:

Or maybe one of these:

Or possibly one of these:

Or even one of these[2]:

Or maybe none of them. Incidentally, a good way to actually get a positive ID on most northeastern-US crane flies is to refer to the Crane Fly Identification Keys that Dr. Chen Young maintains at the Carnegie Museum of Natural History. The only problem for me is that these keys require good pictures of the wing veins, which I mostly don’t have in these cases.

So anyway, the larvae burrow in soil, and ultimately pupate there. Depending on the species they either eat fungus and miscellaneous soil organics, or prey on other species that eat those things. They don’t seem to be active pests of anything, so it is probably more useful to think of them as being roughly equivalent to earthworms in the soil fauna.

A lot of people see the big adults and kind of freak out about them, because they do have a resemblance to mosquitoes. Great, big mosquitoes. Once, when I was in 5th grade [3], one of the other kids brought in a jar with a crane fly in it. He said his dad had told him it was a “Japanese Mosquito”, and that if it bit someone it would drain them dry. I’m hoping his dad was just pulling his leg, and didn’t really believe that, but you never can be too sure about some parents. Anyway, adult crane flies are completely harmless and don’t bite or sting or prey on anything (although I guess some of them will eat nectar and pollen from flowers). The only way I can see them being dangerous, is if you were bicycling or motorcycling and caught one in the eye. I suppose the startlement could make you crash, which is a good argument for wearing a visor or goggles [4].

[1] Sandy has hit on a nice method for making soil for a flowerbed, at least given what we have to work with around here (our soil is about 30% rocks, and the heavy winter snowfalls produce a substantial flow of water every spring when it melts, which tends to leach out all the nutrients.) First, she digs out a trench, and picks out the rocks (to use to make stone retaining walls). Then, she goes to one of our neighbors, who has horses, and loads up a truckload of horse manure. Then, she uses our cheap electric cement mixer to blend the horse manure with the de-rocked soil, and fills it back into the trench. It looks like really nice soil, we will see how the flowers look when they come up this spring.

[2] Actually, it is possible that all of those adult crane flies except for the last one (the one with its wings folded over its back) are the same species. It would evidently be necessary to look closely at the wing veins and the genitalia to be sure, though. These were all different individuals caught at various times, at any rate, and they could all just as easily be different species. There are pictures of both males and females, by the way: the males have kind of a bulbous tip on their abdomen, while the females have abdomens that taper to a sharp point. I didn’t really want to devote an entire post to any one of these adult specimens, though, because they are hard to photograph and have them look decent. Those gangly legs get all over the place, and there are serious problems with the depth of field. For most of these individuals, the photo I posted here is the only one of that specimen that was any good at all. So anyway, now I’ve cleared out most of my outstanding crane-fly backlog. That’s a relief.

[3] I think that was the same year that one of the kids brought in a “moth cocoon”, and the teacher let her put it in a jar so that we could see what kind of moth it was when it came out. I noted that it looked much more like a praying mantis egg-case than a cocoon, but when I told the teacher so she just pooh-poohed me. And then, around the middle of March I was vindicated when we came to class and found hundreds and hundreds of praying mantises all over the classroom! The teacher took me a bit more seriously after that episode.

[4] Do you know how you can tell somebody is a happy cyclist? By the bugs in their teeth! Seriously, when you are riding a bicycle and hit, say, a swarm of midges it can be pretty surprising and more than a slight choking hazard. One of these days, I expect to have something on this site that is tagged “Found in Teeth”.

9 Responses
  1. April 14, 2011

    Love the preying mantis story! Speaking of midges, we saw a column of something small and light-colored dancing in our yard last week on one of the few warm and sunny days we’ve had so far this year. I’ve seen that phenom once before. Are those gnats or midges, do you suppose?

  2. April 15, 2011

    I think I know the ones you mean – the males form up into clouds or columns in a particular spot ( about 3-6 feet off the ground), usually in the morning, and wait for females to fly through. They seem to use some kind of landmarks to stay in one spot, rather than drifting around. They particularly like several spots along the trail I bicycle along to get to work. Catching a swarm of them in the face abruptly is an . . . experience.

    I wasn’t sure whether they were midges or gnats either, so I tried looking it up. As far as I can see, “gnat” and “midge” are poorly-defined terms with considerable overlap, and may actually mean the same thing. Some people claim that “gnats” bite while “midges” do not, but then there are “fungus gnats” which do not bite, and “biting midges” that do, which pretty much blows that theory. So, I think they are probably interchangeable terms. Wikipeda says that the ones that form the clouds (sometimes called “ghosts”) are referred to as gnats, for whatever that’s worth.

  3. Della3 permalink
    April 17, 2011

    Now I’m confused. Apparently, what I was told was a mosquito hawk (and I have passed that information on to many others), is probably a crane fly. However, upon looking up the crane fly on, I find none with the very long, curled up proboscis of my local “crane fly”. Of course, there were so many posted pictures, I didn’t look at every single one. Years ago I was told that this long proboscis would be unfurled by the “mosquito hawk” to suck out the juices of the mosquito. I’ve been gladly welcoming “mosquito hawks” to my property, and even protecting them, ever since. I remember catching the critters when I was young, and marveling at the beautiful curled up “straw” coming out of its mouth. Of course, I haven’t looked that closely at one for years, so I’ll have to check this summer to see if the ones at my current home also have that same feature. I remember pointing it out to some children and telling them it was the reason they did not need to fear being bitten by this large insect, since its “tongue” was too long and soft to penetrate our skin.

  4. April 18, 2011

    Della3: Could it be that your “mosquito hawks” are Hangingflies? These are about the size and shape of crane flies, but they are in a different order (Mecoptera) and are predatory. They have four wings instead of two, and a distinct proboscis (although it doesn’t look like it rolls up). I’ve never knowingly seen one, but they hang from things by their front legs and snag passing insects with their hind legs.

  5. Della3 permalink
    April 18, 2011


    I looked at the pictures from your link, but none of them have the very long, rolled up proboscis, which should be very obvious in the photos. The sources who originally named these creatures for me have been wrong on many such things (the show MythBusters has cleared up a lot of false information for me). Since the proboscis was so long and flexible, I wonder if perhaps it is really a nectar feeder. Nevertheless, I’ve not seen them on flowers, but rather congregating around lights at night, where they will perch on the walls and sometimes remain during the day as well.

    On writing this, it occurred to me to check the back door for any early ones. Yesterday I only looked out the front door. I found one! It’s a very large specimen, too. I trapped it in a square jar and have a very good view of it. There is no rolled up proboscis! Silly me to think all of these creatures in this area would be the same ones from one city to the next. I’m going to see if I can narrow down what type of crane fly it is. This one is particularly handsome.

    This jar is working so well, I wonder if you would find a square jar to be a good photography tool for flying insects. Its especially good for a view of the abdomen. My little point-and-shoot camera even took a fairly decent photograph without the flash. There is some distortion with the glass, but this is a small jelly jar. I’m sure you could find one with much less distortion. If you can’t find a high-quality jar, you could glue a glass box together with disortion-free glass. I think the small size is helpful. There isn’t enough room for the fly to desire very much exploring so after a few seconds it is happy to remain still. If you find that photographing your subjects through glass works well, you could build a number of boxes of different sizes to keep smaller ones calm. You could even build them with a flatter shape to give a closer view of the dorsal side. Or build a box with with one removable side and one side with a slot in it. Make a square glass piece that snuggly fits inside the other sides of the box. Attach a stick or lever to the edge and move it through the slot to bring the glass closer to the insect. I can’t get over how much better I can see this crane fly just because the jar is square!

  6. Della3 permalink
    April 18, 2011

    Well, I spent some time on Dr. Chen Young’s Crane Fly Identification Keys page and also some time on and have learned that my crane fly is a male and probably a Tipula sayi. The wings have the same veining pattern and coloration,or lack of color; the body is the same coloration and shape/size; the antennae have the same number of segments; with my naked eye the legs, genitalia, head, upper body, and other parts seem to be the same colorations and shapes and sizes. My current crane fly has halteres so is definitely not a hangingfly. Apparently some crane flys do feed on nectar. Some pictures of Tipula sayi can be found here:

    Tim’s photo #4 on this posting may be a Tipula sayi. It looks to be a female, and is pictured resting on some grass, where someone on the bug guide said they are often found. The antennae on photo #5 seem to have the same number of segments as the sayi, but I can’t tell if there is a stripe on the edge of the wings. Most of the crane fly descriptions of antennae list more segments than the sayi possess. Photo #8 is clearly a different variety of crane fly. The wings do not have the dark stripe on the upper edge, and there is a darp spot near the end of the upper edge that I saw on pictures of other varieties of crane fly. The stripe down the back of the body is another distinction.

    Robin McLeod had an interesting comment about crane flies under the Tipula sayi search photograph. I was going to paste it in here, but I’m not sure if such comments are included under the content “rights reserved” claim for this contributor to BugGuide.

    Tim, that crane fly pupa is a great find! I’m also surprised that it would move around.

  7. Carly Miller permalink
    April 20, 2011


    I wanted to ask you a question about your site. Would you mind emailing me:


  8. Alexis permalink
    July 17, 2017

    HELP HELP SOS. I FOUND THIS EXACT LARVAE ON MY BED!!!!!!! Is that NOrmal????? I just flushed it down the tolight. I thought it was dead but once it hit the water it wiggled and moved like a freakin WORM! Q- DO THEY LAY EGGS OR SOMETHING?? AM I SAFE TO BE IN MY BED RN??

  9. July 18, 2017

    Alexis: No, it isn’t normal. I would never expect to find one of these coming into a house on its own, and they certainly wouldn’t be able to climb into a bed. Do you have a pet (or a child) that might have carried it in from outside?

    In any case, while they are hideous, they aren’t dangerous. They just turn into crane flies. They can’t breed (or even survive for any great length of time) in a house.

Comments are closed.