Large Crane Fly with Spotted, Folded Wings

2012 November 24

Sam found this large crane fly on June 4, 2011, on our front doorjamb. The first picture shows it in the bottom of a 2.5-inch diameter plastic jar, and its legspan was almost completely across the width of the jar.

I used to think that the way that they hold their wings was a useful species ID feature, because sometimes you see crane flies with their wings folded like this one, while other times you see them resting with their wings sticking out to the side. But then I saw a mating pair where one had its wings folded, and the other had its wings sticking out sideways, so that whole idea is now pretty suspect. The way they hold their wings may be a sex difference, but I think it is just as likely to be personal preference of the individual fly, and often diagnostic of nothing other than its whim at that moment.

After poking around on BugGuide for a while, I thought it looked a great deal like one of the larger Limoniid crane flies. Probably one of the ones in the genus Limonia. I thought it might be Limonia immatura, but that species has three black bands around the upper part of each leg (the femur), and this one only has two black bands on each leg. So it is probably one of the other 142 species of Limonia in North America.

Update: after this post went up, Matt Bertone left a comment identifying it as Limonia cinctipes. And a key ID feature distinguishing it from Limonia immatura is, in fact, the number of black bands on the legs. He also said that they are both in the subgenus Metalimnobia, which is sometimes considered to be a full genus that consists of only a few large, yellowish crane flies. Thanks, Matt!

Crane flies have a characteristic hunchbacked appearance, with large thoraxes to hold the powerful wing muscles that they need to fly. Their heads are generally down underneath the main part of the thorax.

The shape and location of their head is probably so that they can reach the nectar in flowers (at least, in the species where the adults eat). This one has a long enough nose that I expect that it is one of the eating kinds.

4 Responses
  1. Matt Bertone permalink
    November 24, 2012

    You got close and although it is not Limonia (Metalimnobia) immatura, it is a Limonia (Metalimnobia) cinctipes. The latter species has two rings on the legs like yours. The subgenus Metalimnobia is often elevated to genus status now, and thus reduces the possible species to a handful of large, yellowish limoniine crane flies.

  2. November 25, 2012

    Thanks, Matt! I’ve added the information from your comment to the main post.

  3. November 26, 2012

    How come Sam keeps finding these bugs?
    Is she the source for all the criminal creatures on this blog?

    I’ve never seen such a pulled out taffy creature like this.
    She (or he) has very stilt like legs and I never even noted the bands on her legs until you used them to identify her (or him). Well at least you tried to identify her (or him) (you should really tell us if the bug is a girl or a boy so I don’t have to keep doing the her/him business.

    The wings look just like the stained glass in church windows with very beautiful sections cut and pasted into place.

    It is creepy to think that these types of bugs are everywhere about.

    I do feel sorry for this bug—having to be hunched over like this –it is sort of the way I am all day over my poems.
    Except no nectar, no nectar.

    And what do you mean by this part?

    The shape and location of their head is probably so that they can reach the nectar in flowers (at least, in the species where the adults eat)

    Do you mean some of them don’t eat anything after they become adults?
    What do they do then?
    Just mate?
    This seems a very poor way to spend adulthood.
    Although I suppose it would ensure that the species survived if they committed their entire adulthood to propagation of the species.

  4. November 27, 2012

    “How come Sam keeps finding these bugs?”

    Mainly because she likes to find them. Bugs are very much a “seek and ye shall find” sort of thing, and she’s happy to seek them.

    Oh, and the tip of the abdomen comes to a point, which in crane flies indicates that this is a “she”. I forgot to mention that.

    “Do you mean some of them don’t eat anything after they become adults?”

    Yep, that’s exactly what I mean. A lot of insects spend their youth building up resources so that when they finally become adults, they will have a week or so to concentrate on mating and egg-laying before they die. The ones that do this tend to be the larger insects that can carry around large fat reserves, and that are also highly likely to get eaten by birds or bats. Since they might only have a day or two before something eats them, their time as adults is at a premium, so they don’t want to waste any of their valuable mating and egg-laying time on searching for food.

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