news-record.com

The dog-day cicadas, colloquially named for their appearance during the hottest days of the year, have started making their annual noise in North Carolina.

Just don't call them locusts.

These insects are notable for their size -- up to 2 or 3 inches long with wingspans as wide as 4 inches -- and their distinctive bright green markings.

And the noise.

Unlike the steady pulse of a cricket's chirp, the buzz of a cicada gradually climbs in pitch and volume, then falls and stops.

It's heard most often in the morning, as the temperature approaches 80 degrees, said Stephen Bambara, an extension entomologist with N.C. State University in Raleigh. Cicadas have been out for about a month already and will likely be heard for another few weeks, molting and leaving their hard skins all over your yard.

Young cicadas spend years in the soil sucking juices out of roots before digging their way up to the surface to climb trees or anything else they can find.

They only last about two weeks as adults.

''It's kind of backwards to what we're used to," Bambara said.

The appearance of the dog-day cicada also brings out what Bambara calls its "interesting enemy" -- the fearsome sounding (but harmless to humans) cicada killer wasp, which hunts cicadas, puts the carcass in a hole in the ground, lays an egg on it and covers it up. The larvae feed on the dead cicada to grow.

Cicadas are not generally known as pests, in part because there aren't enough of them to seriously damage the plants they live on. And because of habitat destruction wrought by farming and construction, the numbers of annual cicadas are dwindling, according to Bambara. They tend to be found in older groves of trees where the soil is undisturbed.

''You're just not going to find very many of the annuals," he said.

More common are their orange-tinged periodical cousins, who spend 13 years or more in the ground and emerge in huge numbers in the spring of certain years.

That's probably where the confusion with locusts comes from, even though, as Bambara said, they "definitely are not" the same.

In the years when the periodicals swarm, Bambara said, they conjure images of the plagues of locusts (actually a type of grasshopper) described in the Bible.

''If they're all landing on you, if you're in the middle of this thing, it can be very dramatic to look at," he said.

The next concentrated appearance of the periodicals in the Sandhills is expected in spring 2012, Bambara said.

Even then, there's nothing to fear. Cicadas are mostly harmless to humans.

''If you held one tight in your hand, you might be bitten by it," Bambara said. "Otherwise, they're just teddy-bear kind of things."