These flies stick to your windshield | VailDaily.com
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These flies stick to your windshield

Pete Fowler
Vail, CO Colorado
Kara K. Pearson / Post Independent Patti Boas, of Glenwood Springs, sprays her car windows Friday while at Scooter's Car Wash. Caddis flies are hatching and decorating windshields.
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GLENWOOD SPRINGS ” Live fast and die young.

It could be the motto of the caddis flies that flutter into windshields and car grills and nooks and crannies of all manner after a mass hatching from the rivers every spring.

Hundreds of species of insects hatch throughout the year, but the caddis fly hatch-a-thons are one of the more visible events.



They hatch “en masse” to increase the odds of encountering a member of the opposite gender as quickly as possible.

“Most caddis flies don’t even have mouth parts,” Colorado State University extension agent and entomologist Bob Hammon said. “They’re there for one purpose ” to mate, lay eggs and die.”



The caddis flies live in the larvae stage in the rivers in small “cases” they construct for about a year or so. They hatch around this time in the spring and fly around trying to mate and lay eggs while they’re alive ” usually for only a few weeks.

This week clouds of the drunkenly fluttering insects appeared around Glenwood Springs. Their presence here should taper off while more will appear at higher elevations.

They’re sticky when smashed.



“Once they’re dried up, you can’t even scrape them off with a razor blade,” Pit Stop carwash and auto-service station owner H.J. Chee said.

Not even the 1,200 PSI sprayer will knock them off, he added.

Turning up the power on the sprayer higher than 1,200 would knock off mirrors and trim, but not the insect goo. They have to be scrubbed off.

Chee recommends washing them off fast, saying that once they are dried on for more than two or three days they become “like cement” and that acid from their bodies will actually etch through paint on a vehicle.

“It seems to me we have a lot more than we’ve had in about 10 years,” Chee said.

“I think we had a fairly warm winter, which did not kill as many insects,” said Pat McCart, also a CSU extension agent and entomologist.

The “cases” that caddis fly larvae live in are “like little log cabins in the river,” Colorado Mountain College biology professor Bob Kelley said.

The larvae weave nets of silk and glue rocks or gravel together to build the protective structures. Some caddis flies use grasses or silt. Some types construct portable cases and some construct more permanent dwellings, using silk nets to catch food that drifts by.

If they don’t wind up in the belly of a fish, the larvae pupate for a week or two after about a year in the larval stage, and hatch. Females lay eggs enclosed in a gelatinous mass by attaching them above or below the water’s surface. Eggs hatch in about three weeks.

Caddis flies look kind of like smaller, slender moths with a longer, narrower bodies and wings with tiny hairs.


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