COLUMBUS (WCMH) — The warm sunshine coaxed Brood X cicadas into fully emerging in the past week in parts of Ohio. The thrum is unmistakable.

The 17-year periodical cicadas, with orange wing veins and reddish-brown eyes, are chorusing, which is the way the insects communicate, warn off predators, and initiate mating rituals.

The sound can be deafening, upwards of 90 decibels, which is the equivalent to talking over a tractor or lawn mower, especially when there are millions of them swarming, buzzing and clicking around older trees. The sound arises from male cicadas vibrating their tymbals, an organ located on the side of their abdomen, to signal females.

The delayed emergence from the slowly warming soil (64 degrees at 6-8 inches below the surface) has been observed in parts of 15 states this spring, including parts of the western half of Ohio, after spending 17 years underground feeding on tree roots.

The mating season will conclude in a few weeks, after females lay eggs in tree branches and fall to the ground, not to be heard from again for another 17 years in the mysterious biological cycle.

Brood V brought the last loud swarm of cicadas in the spring in 2016 in the eastern half of Ohio. Another brood will appear in southern Ohio in 2025 following a 13-year cycle.

Dr. David Shetlar, an Ohio State University entomologist who has studied the life cycle of cicadas for decades, said that coverage of Brood X has been patchy.

“They’re only in places where you have undisturbed forestland. A lot of our homes and a low of our communities were built on old farmland, and so there aren’t going to be any periodical cicadas there,” Shetlar said.

Cicadas are not poisonous if ingested, but pet owners worry when dogs in particular consume too many and get sick to their stomachs, Shetlar said, “Cats like them as play toys. The males squeak when they’re played with.”

Fortunately are mainly a nuisance, except for some newly planted trees, shrubs and vineyards that can be damaged when the insect’s appendage cuts into the branches.

Regarding recent news about cicada allergies, Shetlar noted, “If you do have an allergy to shrimp and lobsters, you should be careful about eating a cicada.” He added that there is no relation between cicadas and shellfish.

A recent discovery of a fungus that impacts cicadas has caught the attention of insect experts. “There’s a fungus that attacks the cicadas. The cicadas stay alive, but the tip of their abdomen falls off, and that exposes the fungal spores to infect other cicadas,” Shetlar said.