Spring signals the emergence of new life, but one insect — not exactly a welcome harbinger of the season — is expected to soon make its debut this month after 17 years underground.

The 17-year cicada Brood XIV (14) will be wriggling its way up through the soil — after spending its life underground sucking the sap from tree roots — shedding its shell, and descending upon trees and shrubs to find a mate before dying, all within a matter of weeks.

The red-eyed insects won’t make an appearance as immense as Brood X did in 2004, but they will be buzzing, or chorusing as it is formally known, around Southern Indiana within the next 10 days.

“May 20 is kind of a rough date,” said Keith Clay, an IUS biology professor. “It depends on the soil temperature — if it’s cold they might be delayed a little bit, likewise if it’s warm they could come out sooner.

“If people are in an area where there is a lot of them it’s very dramatic — (cicadas) are hard to ignore.”

Kentucky residents are likely to see a substantially higher density of cicadas than Southern Indiana, where distribution is scattered throughout the state. Brood XIV is concentrated in Middle and Eastern Kentucky, Southern Indiana, Southwestern Ohio, Southwestern West Virginia, Eastern Tennessee, Western North Carolina, and in parts of New York, Massachusetts and New Jersey.

Periodical cicadas, like Broods X and XIV, and the 13-year broods, are found only in the United States east of the Great Plains.

There are about 15 periodical cicada broods, and about 3,000 species of cicadas worldwide. The first cicadas were described by William Bradford, governor of the Plymouth Colony, in 1633, and Indiana has a rich history of research on periodical cicadas, according to Dr. Gene Kritsky, a biology professor at the College of Mt. St. Joseph in Ohio and a world-renowned expert on cicadas.

The oldest historical record of Brood XIV in Indiana dates from 1872 when they were observed in Crawford County, Bicknell in Knox County, and New Harmony in Posey County, Kritsky said. The last time this brood appeared in Southern Indiana, there were reports of dense swarms of cicadas in Floyd County.

Though Kritsky said is appears Brood XIV may be disappearing, or merging with Brood X.

Apparently some members of Brood XIV came out of the ground four years early, when Brood X appeared in 2004. Kritsky said it is likely they are avoiding the life cycle of a deadly (to the cicadas, that is) fungus.

Kritsky first became interested in cicadas as a student at Indiana University under Dr. Frank Young.

“[Young] was the foremost expert — he had done some incredible work on periodical cicadas in the 1950s,” he said. “Frank gave this lecture on cicadas, and it hit me — these are the bugs of history.

“I’m sort of a frustrated historian.”

Kritsky goes years without seeing particular broods he is studying, so he also relies on historical documentation, literature and research.

Each brood of 17-year cicadas is actually made up of three different species, but the species are differentiated by appearance and song, and each sings at a different time of day. Only male cicadas sing, in an effort to attract females for mating.

Soon after mating, the males die, but the females go on to lay 400 to 600 eggs in as many as 40 to 50 nests before dying. Cicadas don’t bite or sting, or carry diseases, but the female’s eggs can harm young trees. Those trees can be protected by loosely wrapping them with cheesecloth or pest netting.

Periodical cicadas are actually good for the ecology of the region — their egg-laying in trees acts as a natural pruning that can increase fruiting in succeeding years, their emergence turns over large amounts of soil, and their decaying bodies contribute a massive amount of nitrogen and other nutrients to the ground, according to information supplied by Kritsky.

Not much is known about how the broods coordinate their emergence. Kritsky said there is evidence the cicadas are able to count the years by the fluid in the trees, and the yearly cycle of growth.

IUS biology professor Randy Hunt, who specializes in vibrational communication in insects, specifically leafhoppers, is taking the once-every-17-years opportunity to do some research on Brood XIV.

With a colleague, Hunt has twice visited central Kentucky, where the emergence is expected to be more dense, to record the cicadas while they are still underground. He plans to go back to complete more research in the coming weeks.

“We did get some evidence of some singing underground,” Hunt said. “We do not know for sure — we’ve made recordings of the nymphs and we are hearing enough to get us jazzed up.

“The idea that these things might be coordinating their emergence with underground singing” would be huge, Hunt said. The pair are still in the very early stages of the research and Hunt stressed thus far they have no definitive answer to the question.

One thing is for sure, though, no one will need vibrational communication equipment to hear the song of the cicadas soon.