17-year cicadas to emerge and descend on southeast Michigan this summer | Michigan Radio
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17-year cicadas to emerge and descend on southeast Michigan this summer

Jan 29, 2021

This brood of periodical cicadas emerges every 17 years.
Credit Laura Gilchrist / Unsplash

Though it might seem pretty cold in Michigan now, spring will soon be upon us, bringing with it cicadas from the largest brood in the United States.

Brood X, otherwise known the Great Eastern Brood, is the largest in both geographic range and number of cicadas of the 15 broods in the eastern United States. The cicadas you see each year usually only have three to four year lifespans, and look different from the distincive Brood X cicadas with bright red eyes.


And there are going to be a lot of cicadas—experts estimate anywhere from 30 billion to a trillion. Since 2004, these cicadas have been underground, progressing through their life cycle and feeding on tree roots. 2021 marks 17 years—and the end of their lives.

Russell Howard is an entomologist at Michigan State University. He says the emergence period will be about five to six weeks, beginning in late May and lasting through June.

"And at that point, they mate, they lay eggs in the small branches of deciduous trees, primarily, and then they die, and the eggs hatch and they burrow down in the soil, and start the whole thing all over again."

Howard says cicadas Brood X likely won't venture much further north than Ann Arbor, but them showing up in Michigan at all presents a huge opportunity for entomologists. 

"We won't see them in East Lansing. There's a few entomologists from MSU that venture down. Some, like myself, go to collect specimens for teaching. Others just to see entomological phenomena, because there's nothing like this in the bug world." He adds, "Yeah, to say we're a little geeky would be an understatement."

Howard says the cicadas are not harmful to the local ecosystem, apart from moderate damage to smaller tree branches used as receptacles for their eggs. They can, however, be annoying.

"The males form choruses and vibrate, and they make a lot of racket. That is to draw females to them. And so mostly they’re just a nuisance." He adds, "A lot of things eat these bugs, when they come out. Birds eat them. Pets eat them. You might want to be careful that your dog doesn't eat too many of them. That's about it. Enjoy!"