Bug off! Here come the big, red-eyed cicadas

A "brood" of big, red-eyed cicadas is slowly emerging in the central USA this month after patiently waiting 17 years underground.

The noisy critters are popping out across Nebraska, Iowa, Kansas, Missouri, Oklahoma and Texas.

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The reports so far from Kansas are that this emergence is much larger than 17 years ago, so I'm holding out hope for a good show here this time," said cicada expert Theodore Burk, an entomologist at Creighton University in Omaha.

They've been out over a week around Kansas City and in parts of Nebraska, he said.

There are at least 15 separate cycles, or "broods," of periodic cicadas in the USA. Some emerge every 17 years, while others come out every 13 years. Some species show up every summer.

This year's group is known as Brood IV, the "Kansan Brood."

Different broods of cicadas appear in various parts of the eastern half of the country in varying years, according to the website CicadaMania.

The bugs have never been seen in the West. They feed on sap from deciduous trees (those with leaves) that are mainly found in the eastern USA.

The heavy rainfall that drenched Texas and Oklahoma in May shouldn't bug the cicadas too much, Burk said. "The ground will be pretty saturated, but I don't think that would affect them unless the area where they were living was actually under standing water for a prolonged period," he said.

A separate brood of 13-year cicadas is also appearing this year, in the Lower Mississippi Valley, CicadaMania reported.

The cicadas' loud noise is made by males to attract females. The males contract ridged membranes on their abdomens to make the sound, which is amplified by their almost-hollow abdomens.

Each species has its own sound, and the chorus can reach 90 decibels — as loud as a lawnmower, CicadaMania said.

Cicadas are harmless, though they're big enough to startle humans. The largest ones can have 3-inch wingspans. If enough of them emerge, the crunchy critters can wreak havoc outdoors as they scuttle across parks, patios, decks and sidewalks.

Young, small trees can be damaged when females deposit their eggs inside branches, said John Cooley, a research scientist from the University of Connecticut.

An adult cicada usually lives two to four weeks, which isn't very long after waiting 17 years underground.