We all know that famous quote from Paul Revere, don’t we? “The cicadas are coming, the cicadas are coming!”
Okay, he didn’t say that. But if he were alive today, he just might. And he’d be correct if he were in Michigan.
That’s right, cicadas will take flight in Michigan this spring after 17-years underground -- and it’s going to be loud. This is your guide to the once-in-a-17-year event:
Brood X cicada to emerge in spring
Sometimes referred to as the Great Eastern Brood, the Brood X periodical cicada is a 17-year cicada that last emerged in 2004.
Periodical cicadas spend most of their lives as larva, burrowed in the ground, taking a full 17 years to mature from nymph to adult, feeding on nutrients and fluids from the soil and small roots. When it’s time, the buggers tunnel to the surface and wait for the soil to warm to about 64 degrees.
Hundreds of thousands, perhaps millions per acre can appear simultaneously in some areas, according to U-Mich researchers, leaving behind an exoskeleton as they fly off to sing and mate.
Adult periodical cicadas are black from above and orange underneath. They have bright red eyes and clear, membranous wings with black veins. They’re just over an inch (2.5 centimeters) in length with a three-inch (seven-centimeter) wingspan, according to NWF.
According to the U.S. Forest Service, active broods for Brood X can be found in Michigan, Illinois, Ohio, Pennsylvania and Indiana, as well as scattered through parts of Tennessee, West Virginia and Delaware.
Let’s burrow into some questions we’re all wondering. I talked to Michigan State University entomologist Gary Parsons about the coming cicada emergence -- and what it all means for us in Michigan. Here’s some Q&A:
Where exactly are these broods in Michigan? Where can you see them?
The only place I personally know of where they emerged in Michigan in 2004 was at the Cherry Hill Nature Preserve on the northeast side of Ann Arbor/Ypsilanti.
In the early 1900′s they used to be more widespread over much of the lower peninsula. However, now probably due to the effects of logging, conversion to agriculture, development and other human activities, they are now very much reduced here. Places like the nature preserves which have remained untouched have served as refuges for them.
When they emerge cicadas generally do not move far from the emergence site, since that is where they hope to find mates. Also isolated cicadas outside the emergence area would be more likely to be picked off by predators. So they are always found in a specific area from emergence to emergence, and I expect they will still be at or near Cherry Hill again this year. So if people want to see and hear them, they will need to travel to see them.
But there are lots of places down in southern Indiana and Ohio where the emergence might be much larger and more spectacular. Visit some of the websites or watch the news for possible places when they come out. Maryland and southeastern Pennsylvania are also big hotspots, but much farther to get to.
Are there other species of cicada in Michigan?
Brood X, the largest and most widespread brood in the U.S., is the only brood that can be found in Michigan.
There are six species of periodical cicadas with populations scattered around the eastern United States that emerge in different years called broods. Each brood is isolated in a certain region and only emerges in that area in 13 or 17-year cycles and won’t be seen in the intervening years. However, a different brood may be emerging elsewhere in the U.S. during intervening years.
So, nearly every year somewhere in the eastern U.S., a brood will be emerging. The 17-year broods seem to occur mostly in the northern U.S. and 13-year broods emerge more to the south. In some years, both a 13 and 17-year brood will emerge, but not in the same location. In some years, no cicadas will emerge.
Annual cicadas, which are more commonly seen or heard here in Michigan, only have a three or four-year life cycle. As their name implies, some emerge every year, and these are the ones we hear singing every summer. However, compared to the periodical cicadas, they emerge in much lower numbers in any given area. There are several species of annual cicadas here in Michigan and they can be distinguished by having different songs.
Do cicadas pose any threat to plants, animals or humans?
Cicadas do not bite and are harmless to humans and property — other than being a nuisance. They may amass in millions in parks, woods, neighborhoods and can seemingly be everywhere. When they are this abundant, they fly, land and crawl everywhere, including occasionally landing on humans.
Cicadas will not enter homes, but they will amass and rest on outside walls. The only way they could get inside is accidentally flying in through an open door or window, or because they had landed on a person who then carried them inside unnoticed.
With millions of adult cicadas emerging at once, predators tend to have a feast on them. Sometimes dogs or pets will gorge on so many of them it will make them sick, but they are not toxic or otherwise harmful.
What is the typical life cycle for a cicada after it emerges?
Once a cicada nymph emerges from the ground and sheds its skin to become the adult, it will only live a week or two. They don’t feed much or at all as adults, with all their energy devoted to finding a mate and for the females to lay their eggs. The females use a sharp ovipositor to insert their eggs into twigs and branches. After that they die off by the millions.
After a month or so the eggs hatch into tiny nymphs which drop to the ground and burrow down to find a tree root to start feeding on for the next 17 years.
Why do cicadas make so much noise?
It’s a mating call. Cicadas make sounds in quite a few ways: with tymbal organs, wing flicks, wing clicks, and stridulations. Read more from Cicada Mania.
Why do these cicadas remain underground for 17 years?
Periodical cicadas have been doing their 13 or 17-year cycles for probably millions of years. It is thought that by having the long life cycles, cicadas have prevented predators from specifically targeting them for food. Then by emerging in the millions all at once, they are too numerous for any predators that do eat them from ever wiping them out. There are so many of them that lots of them will always survive.
In the long ago past, it is likely the different broods were more widespread geographically. It is likely that urbanization, widespread commercial farming and other factors have reduced and limited them over the years.
It is likely that Brood X was once more widespread in Michigan, and we have a few old records in our collection to support this.
When should we expect to see cicadas this year?
Supposedly the emergence begins when the soil temperatures 8″ down reaches 64 degrees. However some individuals will emerge over several weeks, so the total emergence may last over a month and usually occurs in late May into June depending on the area.
In 2004 they emerged around the first of June at Cherry Hill, but they probably came out earlier further south in the US.