Saturday, September 10, 2011

Late summer bumblers.

Crane flies: spend half their time trying to get into the house, the other half trying to get back out.

Perhaps in recent weeks you’ve encountered large, winged creatures resembling nightmare-sized mosquitoes that, when you open the door of your home, unerringly fly at your head, and perhaps flutter up against your ear with a clumsy clattering of wings.  If this has happened to you, you have experienced a crane fly.  Creepy? Perhaps, but harmful? Not at all.

Crane flies are identified by their extremely long legs, long bodies, and single pair of clear, narrow wings that stick out almost perpendicularly from the body.   Often the body is orange. There are more than 14,000 species of crane fly worldwide and 1500 species in North America.  They range in size from a few millimetres to several centimetres. Like mosquitoes, midges, house flies, and other “true flies,” they have a single pair of fully functional wings, and behind these, the vestiges of a second pair known as halteres.   In crane flies these resemble little paddles, and are thought to aid in flight –although, judging by the aerobatic skills of some, one wonders if the owners have been informed how to use them.

 Flying ability may be gender related.  Females are reported to fly in steady, straight lines, whereas males fly erratically, undulating and rotating.  You can interpret that any way you like. Perhaps the one that blundered into you was a male, impetuous, but not very focused.

Crane flies lay eggs in water or on low vegetation, depending on the species. The maggot-like larvae, which may live a year or more, dwell in the mud of stream beds or within forest litter where they act as detritivores , eating partially decayed organic material.  They thus help in the cycling of nutrients.   The larvae of some species may live within the soil of gardens and lawns.  They tend to be relatively large and thick-bodied, with tough brown or black skin, and are commonly known as “leather jackets.” Some consume the living roots of grass, and can damage turf.  They are not popular on golf courses.

Typical of largish, odd-looking and poorly-known creatures, crane flies are subjects of myths, one being that they bite, a second that they eat mosquitoes.  In some places they are called “skeeter-eaters.”  In reality they do neither.  Although freaky-looking and clueless regarding personal space, they’ll do no harm.  The adult, winged stage is very short lived, meant to breed and lay eggs, and not much else.  Most live only ten to fifteen days, and during this time many don’t eat at all.  Those that do, stick to nectar. The long-legged thing on the window is the last hurrah of the crane fly’s life.  It is at this stage that they also become prey to insect-eating organisms, everything from carnivorous plants to frogs, birds and bats.  Being consumed would thus be their final purpose.

If you encounter one, or if one wanders indoors, be not afraid.  They are easily swatted, if you feel the need, or with a little effort can be trapped in an empty jar and relocated to the garden.  In any case, their visits are short-term.  Very soon they will be gone.


KaHolly said...

Really!! My experience, exactly! They surely made me curious and I finally had to look them up to learn their story! Great post.

Tim said...

Crane flies do serve a purpose in my home. Easily caught, I hold their franticly beating bodies by the wing, and lure problematic (ie. the ones my wife complains about) spiders out of their cobwebs so I can easily relocate them.