cicada
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The last cicada swarm in the US was in Virginia in 2004

Another natural phenomenon has hit the Southern States as swarms of cicadas return after 13 years hibernating underground.

Every 13 years the inch-long insects emerge from their underground lairs to plague America's Deep South in a feeding and breeding frenzy.

It adds to the natural phenomena the region has battled with after tornadoes last month and floods in Mississippi this week.

Apart from their intense 120-decibel mating racket and the frustration of finding them in hair, clothes and lunch-boxes, they're completely harmless to humans.

Scientists call them the Great Southern Brood or Brood XIX and are eager to study them before they disappear until 2024 in about four to five weeks.
Fact Box: Southern USA Cicadas

:: Cicadas in the southern US are the largest variety in the world.

:: Brood XIX were last active in 1998

:: They hibernate in exoskeletons

:: Young cicadas start to sing 4-5 days after emerging
Carol Reese, horticulture specialist at the UT Agricultural Extension, told the Jackson Sun: "They have red eyes, they don't sting, they don't bite."

"It scares the heck out of you when they buzz, but they really don't do you any harm."

Gardeners and farmers have more cause for concern.

Protective netting has been assembled to protect trees and crops from their feeding nodules as they attempt to bury into branches and suck out nutrients.

Female cicada cut deep slits down branches thinner than a pencil to lay eggs that hatch six to eight weeks later.

Younger plants can buckle under the strain of housing too many larvae.
Newly emerged adult cicadas, seen at different stages of drying their wings, wait on a tree.
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Cicadas are white with bulging eyes but develop hard, brown skin

But not everyone is dreading the insects, who are often confused with locusts though actually related to leafhoppers.

Fishermen are eagerly anticipating the return of their perfect bait.

Keen fisherman Gil Lackey told The Tennessean: "For the past six months I have been emailing and posting on chat boards, 'Quit your job, divorce your spouse and sell the kids; you need to go fishing'.

"All the fly fishermen are pumped up. It's crazy fishing when the cicadas are hatching."

Only three of the 15 varieties or "broods" come every three years.

The other 12 varieties - including those that invade the Northern States - arrive every 17 years.