Billions of cicadas emerging amid rare double brood. Will Canadians get to see?

The two broods - one in U.S. Midwestern states and the other in the South and Midwest, with a small area of overlap in Illinois - emerge together only once every 221 years.

In a rare natural phenomenon that has not been witnessed since the 1800s, illions of cicadas are poised to emerge from their decades-long slumber across the eastern half of the United States this spring and early summer.

This double brood event will happen just south of Canada, with both 13-year and 17-year cicadas emerging simultaneously, which has not happened since 1803, when Thomas Jefferson was president. And the next time this will happen will be in 2,245.

“This is a big, big event,” said David Beresford, an entomology professor at Trent University in Oshawa, Ont. “Just like the solar eclipse, the cicada emergence is probably once or twice in a lifetime event that will be able to take advantage of, and I am quite excited.”

He stressed that these insects are harmless to humans and are “actually quite cute. They look like little tree frogs, probably one of the most endearing insects out there.”

The spectacle is set to unfold across the eastern U.S., with its northernmost boundaries extending into Illinois. Although this may be as far north as the event happens, Beresford still hopes it may appear in southern Ontario too, but admitted to speculating and remaining hopeful as an insect enthusiast.

“I hope that we catch the very edge of those and get to see it,” he said. “But it will be worthwhile going to the States to be part of this.”

Cicadas are known for their loud buzzing chorus that fills the air during mating season on warm summer days. There are more than 3,200 species of cicada worldwide, according to the Smithsonian Museum of Natural History. In Canada, Beresford said there are several species but they are “annual cicadas” meaning they may emerge from the ground every season.

In contrast, the rare double-brood event in the U.S. involves periodical cicadas that synchronize their emergence during 13 or 17-year cycles, Beresford said. Periodical cicadas occur in different regional “broods,” each consisting of one or more species with the same cycle length.