By Tim Gardner
Be listening for a constant loud, piercing and humming sound across the North Carolina High Country because you’ll soon hear it when you’re outdoors.
During the spring, this region, as well as the entire eastern United States will host one of nature’s most unique creatures — periodical cicadas. These mysterious insects live underground either 13 or 17 years before emerging for a few weeks of furious mating, while making the famous or infamous sound (depending on your point of view). These insects mating is then closely followed by mass death.
The 17-year cicadas are divided into 12 different broods, each of which emerge on a different schedule and occupy different geographic areas. The 13-year cicadas, comprised of a separate set of species, are divided into three broods.
The Brood XIV Cicadas won’t emerge again until 2025. Its populations are concentrated along the Appalachian foothills, mainly in Tennessee and Kentucky, but also including parts of North Carolina, Virginia, Ohio and West Virginia as well as a few places in Massachusetts and Pennsylvania.
But the Brood X, is the most widely distributed of the 17-year cicadas. Scientists have declared that billions combined of Brood X will emerge this spring in Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Washington D.C. and all regions of North Carolina. Scientists have noted that parts of each of those states will likely have millions of cicadas, including in the North Carolina High Country.
For 17 years, these insects that are set to appear this spring have been underground, growing little by little as they feed on tree and shrub roots. Now that it’s their year to emerge, they’re waiting for the right temperature. In the warmer parts of their range, they tunnel to the surface in late April or early May. But here in the mountains, it may be in May or early June.
According to insect experts, some cicadas will begin to emerge, and that induces many others once they start calling.
Cicadas remain aboveground for four to six weeks after the first emergence. During that time, males congregate in “choruses,” usually in high, sunlit branches, where they create their noted sound using the ridged membranes on their abdomens called tymbals. Females don’t have these sound-producing organs, so the sound serves to guide the females to the choruses of males. They then meet and mate.
Soon after mating, females split the bark of living trees and shrubs and deposit their eggs, usually between 24 and 48 at a time. However, females can mate many times during the course of an emergence and may lay up to 600 eggs before their death at the end of the emergence. The eggs remain in the trees for six to 10 weeks, at which point the juveniles hatch, drop to the ground, and burrow into the soil, where they will remain for another 17 years.
There are about 150 species of cicadas in the United States and 3,000-plus worldwide. However, the seven species in the eastern United States known as periodical cicadas are unique among them. These species — four on a 13-year cycle and three on a 17-year cycle — are the only ones that combine an extremely long nymphal stage with a synchronized mass aboveground emergence.
The 1.5-inch-long insects don’t bite. They actually don’t have teeth. However, they are loud during the daytime hours, though they don’t sing at night. Some of the more raucous choruses can exceed 100 decibels as perceived by somebody standing directly under the tree where they are located. Adult cicadas eat tree sap through a proboscis, and while their meals are unlikely to do any real damage even to young trees, it may be best to cover young woody plants with bird netting or another cloth in order to avoid damage from females as they pierce small branches to insert their eggs.
To learn more about these insects, log online to: www.cicadamania.com.