Monday, March 31, 2008

Monday Myth: Crane Flies

Adult Crane flies mating
(family Tipulidae)

Crane flies belong to the family Tipulidae, and are not "giant mosquitoes", or even mosquito-eaters ("skeeter eaters" is their common name where I come from). Adult Crane flies don't suck blood, they don't bite, pierce, or sting. In fact, the adult life stage lasts just long enough to breed, so many species forego feeding altogether (those that don't are nectar feeders). You can't get any more benign that that.

They are similar to mosquitoes with their long legs and snout-like head. A minority number of Crane fly species are even small enough to mistake for a mosquito at first blush. But the majority of Crane flies are 1-2". They belong to the Diptera order of insects (flies), and as such their second pair of wings is modified into little navigational nubbins called "halteres". The halteres act as a rudder of sorts, and are easier to see in Crane flies than other smaller flies. They're located behind the front wings, and are short with a club-like tip.

Crane flies are a floppy flier, and if one happens to fly into your ear or something (which they do pretty often because, with all due respect to nature, they seem pretty stupid), then you might hear their wings give off a faint, low buzz. But most of the time they're a quiet flyer, just looking for a dark, undisturbed place in your home to hang out (on walls, in closets, bathrooms, last week I found one resting in my cat's litter box -- kinda gross).

The larvae aren't well described. They're small, and either soil-dwelling or aquatic (freshwater). Some of the aquatic species of Crane fly larvae eat mosquito larvae. The soil-dwelling larvae sometimes feed on the roots of plants, and are maligned as turf pests when they do. Golf courses really don't like them.

The adults may be nuisance pests, but they don't pose a significant health threat. They're pretty fragile and squash easily. Keeping screen doors closed is the best way to prevent them from coming inside. We've had a ton of Crane fly activity here in the southwest for about a month. By May the rest of the country should be enjoying their floppy-flying fun.

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