Maryland's Huge Cicada Brood, Not Scheduled To Emerge Until 2021, May Be Coming Up Early

BALTIMORE (WJZ) -- A brood of 17-year cicadas not scheduled to emerge until 2021 may be coming out of the ground early, WJZ's Alex DeMetrick reports.

"Brood X" last emerged in 2004, and the bugs appear all over Maryland, as far north as northern New York, as far south as Georgia and as far west as Illinois.

University of Maryland professor of entomology Mike Raupp says that brood appears in massive numbers, and may be headed above ground four years early, but he doesn't know why.

"We can see dozens of holes in the soil, this is where the cicada nymphs emerged over the past several days. They made a mad dash over to this tree. If we look carefully we can see some of their shed skins on the bark of the tree still," Raupp says.

Science isn't certain if they're from a group called brood six, emerging right now mostly in the Midwest, or early arrivals of Brood X.

Raupp is asking people to report cicada sightings on BugOfTheWeek.com to gauge their numbers.

"This is going to help cicada experts to limit the range of this Brood VI or the acceleration of Brood X," he says.

"Brood X last emerged in 2004. It's due again in 2021, but if it's an acceleration, hey, they're coming out in 2017," he says. "We don't really know for sure what the acceleration is all about."

According to the University of Maryland Extension, "adult periodical cicadas live between two and six weeks after they emerge from the ground."

The adults lay eggs a week or so after emerging, and the eggs take another six weeks to hatch.

The babies, or "nymphs," then burrow into the soil and feed on the sap of tree roots until they follow in their parents' footsteps and come to the surface 17 years later.

This cycle exists because, "by coming out en masse, periodical cicadas are able to avoid or overwhelm enemies," according to the UMD Extension. "No predator can possibly eat that many cicadas, chances of individual reproduction and survival increase."

Old records show it's happened before, but four years early seems pretty early.  If it is Brood X, Maryland's in for a lot of cicadas.

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