Urban Nature Pictures day 20; 50 more Urban Species #2: Winter Crane Fly

[urbpan]

Winter Crane Fly, Trichocera sp. (pretty sure, although that urban entomology handbook would be very helpful right about now)

Twice in different workplaces I have been present when this insect caused alarm. First was at Drumlin Farm, on the mosquito netting meant to protect captive birds from West Nile Virus. (I posted about it, but I'll be darned if I can find that post.) It was long past mosquito season, and it made me nervous: just how many months a year did I have to worry about these things? Well, I learned it was a crane fly, a harmless creature that looks mosquitoish. I had previously known crane flies to be quite large insects, much bigger than mosquitoes, but it turns out there are many species of many sizes, and this kind was just the right size to fool me.

Then last week, a coworker called me over to a dumpster on zoo grounds, mostly empty but for some debris and puddles. Here it was early January and it was swarming with flying insects--quite mosquitoish in appearance. I swung my hat through the swarm and snagged one to look at, expecting to see a non-biting midge. Instead I recognized the small crane fly from six or seven winters ago. Today I found one resting on the ice on the roof of a golf cart, and took the picture above.

If you're still having a hard time distinguishing this animal from a mosquito, look first at the posture. Most mosquitoes stand with their heads down and their rears up, with their back legs up like the dainty pinkies of a tea drinker. They also have scales along the veins of their wings--a difficult field marking to notice at a distance, perhaps, but distinctive once you learn to see it. And of course, their mouthparts are very different--mosquitoes bearing cruel and complex probosces to exsanguinate us (or somewhat reduced probosces to draw up nectar if they are males) while winter crane flies, well, you can see their mouthparts are a blunt little affair. I haven't found out what it is that they eat, and they may very well eat nothing at all--a situation not that unusual among insects. Their larvae live in and eat wet rotting organic material.

Some winter crane fly species survive as inactive larvae or pupae from spring to fall, and emerge as adults in winter to breed. This schedule allows them to avoid most of the aerial predators like dragonflies, swifts, and swallows. Their maggots are likewise protected from flesh flies, rove beetles, and other insect predators. Winter crane flies are sometimes called "winter gnats" especially in Britain.

Comments

[wirrrn.livejournal.com]

They eat nectar, decomposing detritus, or nothing *g*. A few species over here prey on mosquitoes too!

btw- The legs are almost impossible to keep intact when you're putting one in an insect collection!

[badnoodles.livejournal.com]

I don't think there's a guide out there that goes beyond genus level on these things. Trichoceridae isn't a particularly sexy family group.

[ndozo.livejournal.com]

What is the point of winter if there are just going to be bugs anyway?!? I suppose birds eat them. Are these related to mosquito lions (not sure of the right name, those giant sort of mosquito-shaped summer bugs like in the picture)?

[kryptyd.livejournal.com]

I only know one type of crane fly and it's what's called a daddy-long-legs here. Those ones are pretty huge, and I know lots of people who are scared of them. They're harmless but people who don't like them swear that they fly at human faces! I think this is either their imagination, or maybe at night time (when they usually come into houses) the flies see the electric lights reflected off people's faces and then fly towards them. That does't explain why they only fly into the faces of people who are afraid of them of course.

[ndozo.livejournal.com]

http://my.ilstu.edu/~jrcarter/ice/diurnal/wood/

Off topic. Cool looking kind of ice and the explanation. Maybe you'd be interested.