Many periodical cicadas emerged four years early in the Chicago area in 2020. These cicadas belong to the Brood XIII (13) which is set to emerge in 2024, and last emerged in 2007. Periodical cicadas often emerge in years proceeding or following the year their brood is expected to emerge. This phenomenon is called straggling. Most of the time these “stragglers” emerge in small numbers and are quickly eaten by predators, and do not go on to sing, chorus (synchronized singing for the purpose of attracting females), mate, and lay eggs. Sometimes they emerge in numbers large enough to survive, chorus and reproduce — this seems to have happened in the Chicago area in 2020. It is thought this this is how new broods formed over the millennia — cicadas emerge 4 or 1 year early in significant numbers and form a new brood. When enough stragglers emerge to successfully reproduce it is called an acceleration.
So, is a new brood forming around Chicago? Is this due to climate change or localized “heat islands”? Will the progeny of these stragglers emerge in 13, 17 or 21 years? Lots of questions — but we’ll need to wait quite some time to answer them.
There is a precedence for Brood XIII cicadas straggling in the Chicago area:
In 1969 massive numbers of periodical cicadas emerged in the Chicago suburbs 1 (Williams, K.S. & Simon, C. 1995).
In 1986, another 4-year acceleration was observed in the Chicago area by Monte Lloyd 1.
In 2003, many people left observations on our forums. Observations were made in Glenview, Flossmoor, Riverside, Downers Grove, Homewood, Westmont, Oak Park, and Hinsdale. Here are some examples:
Magicicada emerging this evening
Date: Wednesday, Jun/4/2003
Message: As I went for a walk this evening I noticed quite a few periodic cicadas emerging in the grass, crawling on the sidewalks and on the trunks of trees. This is not our year for the 17-year brood. We should not have them until 2007. Has anyone else in the Chicago area seen these cicadas? — Sue, Flossmoor, IL
Cicada singing
Date: Monday, Jun/9/2003
Message: I heard the cicadas singing for the first time this morning after my walk. Now that I have my doors open I can hear them on and off. — Sue, Flossmoor, IL
In 2020 many people left comments on the Brood XIII page, emailed us (thanks Neil) and left sightings via the Cicada Safari app.
📅 Brood IX (Nine) emerged in 2020 in North Carolina, Virginia and West Virginia. “Stragglers” from other broods also emerged in limited numbers: Brood X (1 year early), Brood XIX (4 years early) and Brood XIII (4 years early). Here’s a map where they emerged:
Researchers need your help! If you see a cicada, please report it using the Cicada Safari App 📱, available for Android and Apple phones. See a Live Map of sightings.
Magicicada Brood Chart
The Brood Chart features the names of the broods (Roman numerals), their life cycle length, when they will emerge next, which states they’ll emerge in, links to Maps, the species that will emerge, and other information. Click the maps for larger, detailed maps.
Species: M. tredecim, M. neotredecim, M. tredecassini, M. tredecula.
States: AR, IL, IN, KY, LA, MO, MS, TN
When will they emerge?
📅 🌡️ Generally speaking, these cicadas will begin to emerge when the soil 8″ beneath the ground reaches 64 degrees Fahrenheit (Heath, 1968). A nice, warm rain will often trigger an emergence. They typically emerge in May but have been known to emerge in late April or early June. It all depends on the weather.
What should you look for before they emerge?
Chimneys / Turrets
Look for cicada chimneys a.k.a. turrets. These are structures cicadas build out of the soil, positioned above the hole where they will emerge.
Holes
Look for holes the diameter of an adult’s finger near the root system of a tree. These are sure signs that cicadas will emerge in the area.
Cicadas Under Stones & Slates
You might discover some cicada nymphs while turning over stones or when performing landscaping chores.
This is a recently emerged nymph crawling up a tree. Note that its eyes are red.
Once cicadas nymphs have emerged from the ground, they will try to find a tree (or similar vertical surface), and then begin the process of shedding their old nymph skins (ecdysis), expanding their wings, and changing to their adult coloring. Watch this amazing transformation.
How to tell the difference between the seven Magicicada species:
The first way is based on the Brood. Take a look at the Brood chart above, and see which species appear with the Brood.
There are 3 basic types of Magicicada: “‘Decims”, “‘Cassini” and “‘Deculas”.
Magicicada neotredecim Marshall and Cooley 2000. 13-year life cycle. Broods: XIX, XXIII.
Magicicada tredecim (Walsh and Riley, 1868). 13-year life cycle. Brood: XIX, XXII, XXIII.
Their songs are very similar, however, when M. neotredecim & M. tredecim emerge in the same location, M. neotredecim’s song takes a higher pitch. Sounds like “Pharaoh, Pharaoh!”.
Visual Appearance:
Male on left; Female on right.
M. neotredecim & M. septendecim have broad orange stripes with more orange than black on their abdomens.
M. tredecim, by comparison, have almost entirely orange abdomens.
M. septendecim also have an area of orange coloring between the eye and the wing (pronotal extension).
“Cassini” aka Dwarf Cicadas
There are two species in this category:
Magicicada cassini (Fisher, 1851). 17-year life cycle. Broods: I-V, VIII-X, XIII, XIV.
Magicicada tredecassini Alexander and Moore, 1962. 13-year life cycle. Broods: XIX, XXII, XXII.
Their songs are essentially identical:
M. cassini Call and Court:
Note how it makes a quick burst of sound, followed by some rapid clicks.
Visual Appearance:
Female on left; Male on right.
M. tredecassin & M. cassini have black abdomens with virtually no orange at all. Orange stripes are possible in the mid-west (important to note for Brood IV).
“Decula”
There are two species in this category:
Magicicada septendecula Alexander and Moore, 1962. 17-year life cycle. Broods: I-VI, VIII-X, XIII, XIV.
Magicicada tredecula Alexander and Moore, 1962. 13-year life cycle. Broods: XIX, XXII, XXIII.
Their songs are essentially identical:
M. tredecula Call:
Note the “tick, tick, tick” rhythm of the call.
Visual Appearance:
Female on left; Male on right.
M. septendecula & M. tredecula have stripes that feature more black than orange. Otherwise, they’re very similar to M. cassini.
How to figure out if they’re coming to your town?
Verify that they’re coming to your state. Check the Magicicada Brood Chart on this page.
Check Cicada Brood Maps linked from this page to see if they’re coming to your general area.
Check to see if they’re coming to your neighborhood. Good sources include:
Ask someone who lived there 17 (or 13) years before.
Old timers (hint: old timers usually call them locusts).
Check your local Library for old newspaper articles.
Check with a local college: contact the entomology, forestry, or agriculture-related departments.
Your local national, state, county and town parks department (parks and rec). Some county parks departments plan events around cicada emergences.
When will they emerge?
They will emerge sometime in the Spring, for sure.
They typically emerge once the soil 8 inches (20 cm) below the surface gets to 64 degrees Fahrenheit (18 degrees Celcius). At that temperature, they will start digging their tunnels to the surface. After a couple of days with above-ground temperatures near the 80’s F, and after a good rain, they will definitely emerge. Read this paper for more info: Thermal Synchronization of Emergence in Periodical “17-year” Cicadas (Homoptera, Cicadidae, Magicicada) by James Edward Heath, American Midland Naturalist, Vol. 80, No. 2. (Oct., 1968), pp. 440-448.
Cicadas in sunny areas of your yard will emerge before cicadas in shady areas.
Cicadas in the southern-most states will emerge before cicadas in northern states.
Question: Why do I have cicadas in my neighborhood, but your chart indicates that I shouldn’t?
Answer: Some possibilities: 1) they are stragglers, periodical cicadas that emerge too soon or late, 2) they are not periodical cicadas, but are a different North American species, 3) you live on a continent other than North America, in which case, try one of these pages, or 4) SURPRISE! The U.S. is a big place and some cicada populations have yet to be documented.
Question: Why don’t I have periodical cicadas in my area, but the information on your website indicates that I should?
Answer: Two possibilities: 1) they went extinct or otherwise died off in your area, or 2) they aren’t everywhere in a state – normally there are large gaps in their range.
Question: What are stragglers?
Answer:Stragglers can emerge 1 or 4 years early or 1 or 4 years late. Don’t be surprised if you see some periodical cicadas emerge earlier than planned this year. 17-year brood members are most likely to straggle 4 years early, and 13-year brood members are most likely to straggle 4 years late. Straggler probability chart.
Question: Why are there no Brood XI, XII, XV, XVI… ?
Answer: Perhaps you’ve noticed there are no Broods XI (11), XII (12), XV (15), XVI (16), XVII (17), XVIII (18), XX (20), XXI (21), XXIV (24), etc. Don’t worry about that. They never existed or are extinct (XI, XXI).
More Magicicada websites:
For much more information about 17-year cicadas visit Magicicada.org. The maps on this page link to that site.
The Cicada Safari App is available for Android and Apple devices 📱. Use it to see where people are finding cicadas, and to report your own sightings.
Check the Cicada Central Magicicada Database to see the counties where cicadas have appeared in the past. For more information about this database and cicada research in general, visit the Simon Lab website.
In 2020, the main periodical cicada brood expected to emerge in the U.S. is Brood IX (9). Brood IX will emerge in southern West Virginia, western Virginia, and a small portion of north-western North Carolina. This we know for sure.
If you want to see where cicadas are being reported, try the Cicada Safari App is available for Android and Apple devices 📱.
OK, here’s the point of this article:
Cicadas from other broods will also emerge this year in small numbers. When cicadas emerge early or late, they’re called stragglers. Don’t get hung up on the meaning of the word. If it makes you happy, call the ones that emerge early “precursors”, “pioneers”, or “heralds”.
Members of Brood XIX (19) are emerging in parts of North Carolina and Georgia, where Brood XIX is know to exist. There’s some discussion of this over on the Cicada Discussion, Science and Study Group on Facebook. You might see them in Alabama, Arkansas, Georgia, Illinois, Indiana, Kansas, Kentucky, Lousiana, Missouri, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, and Virginia.
The rest of Brood XIX will emerge in 2024. Here’s a map.
Members of Brood XIII (13) are likely to emerge 4 years early in Iowa, Wisconsin, Illinois, Indiana, and possibly Michigan.
The rest of Brood XIII emerge in 2024 (a big year for periodical cicadas). Here’s a map.
Some members of Brood X (10) should emerge 1 year early in Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, North Carolina, New Jersey, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Washington D.C.
The rest of Brood X will emerge next year in 2021. Here’s a map.
Here’s a screen shot from the Cicada Safari app:
Within the app, you can zoom in to see where the cicadas are appearing. Here’s a “Live Map” of the sightings from the app.Pinch and zoom to get details.
Periodical cicada Brood IX (9) emerged in the spring of 2020 in North Carolina, Virginia and West Virginia. The last time this brood emerged was in 2003. It will emerge again in 2037.
Researchers need your help! If you see a cicada, please report it using the Cicada Safari App 📱, available for Android and Apple phones.
Brood IX is interesting to researchers because it’s located very close to 5 other broods. In a normal year, researchers would be able to drive the roads of the area and map the location of the brood so we can get data as to where the broods intersect, but because of the current situation in the U.S., most if not all researchers will be able to travel — so we need you to let us know where they’re at. Read more on Magicicada.org.
What, when, where, and why:
What:
Cicada insects with a 17-year life cycle.
Some people call them “locusts” but they’re really cicadas.
📅🌡️ When: Typically beginning in mid-May and ending in late June. These cicadas will begin to emerge approximately when the soil 8″ beneath the ground reaches 64 degrees Fahrenheit (Heath, 1968). A nice, warm rain will often trigger an emergence.
Other tips: these cicadas will emerge after the trees have grown leaves, and, by my own observation, around the same time Iris flowers bloom.
🗺️ 🇺🇸 Where:
Virginia municipalities: Blacksburg, Bland, Callands, Christiansburg, Covington, Dry Pond, Ferrum, Martinsville, Roanoke, Salem, Vinton, and more.
Virginia counties: Allegheny, Bland, Franklin, Henry, Montgomery, Patrick, Pittsylvania, Roanoke.
North Carolina municipalities: Chestnut Hill, Ennice, Francisco, Hays, Kernersville, McGrady, Millers Creek, Mt Airy, North Wilkesboro, Purlear, Thurmond, Westfield, and more.
North Carolina counties: Ashe, Alleghany, Forsyth, Stokes, Surry, Wilkes.
West Virginia municipalities: Camp Creek , Elmhurst, Hinton, Jumping Branch, Spanishburg, and more.
West Virginia counties: Fayette, Greenbrier, Mercer, Monroe, Pocahontas, Summers.
A quick tip using data from the Cicada Safari app team:
Cicadas in the north-west areas are Brood IX (red). Cicadas south & east of that area (purple) are Brood XIX emerging early.
Not sure? Ask someone in your community who lived there 17 years ago.
Why:Why do they stay underground for 17-years? The prevailing research suggests they’ve evolved a long, 17-year lifecycle to avoid predators that can sync up with their lifecycle & emergence. Why are there so many?! Research suggests that their huge numbers allow them to overwhelm predators, so enough of them will live on to breed and perpetuate the brood.
Some Brood XIII “stragglers” emerged early in 2020. If you see a cicada and want to report it, the Cicada Safari App is available for Android and Apple devices 📱.
A particularly large amount of Brood XIII cicadas are emerging early this year. Here’s a news article and a note from the Illinois Extension. Thanks Neil for the links.
One thing that is important to determine is whether any of the off-schedule populations (especially the 4-year early and 4-year late ones) are large enough to persist and lay eggs. The big question is will they establish a new population? Please send photos of cicadas laying eggs. And if egg laying is extensive enough to damage branches, please send photos of that as well!
Some Brood XIII cicadas are emerging 4 years early, particularly in the Chicago area in 2020. Blue in the map below:
Periodical cicada Brood XIII (13) will emerge in the spring of 2024 in Iowa, Wisconsin, Illinois, Indiana, and possibly Michigan. The last time this brood emerged was in 2007.
When: Typically beginning in mid-May and ending in late June. These cicadas will begin to emerge approximately when the soil 8″ beneath the ground reaches 64 degrees Fahrenheit. A nice, warm rain will often trigger an emergence.
Other tips: these cicadas will emerge after the trees have grown leaves, and, by my own observation, around the same time Iris flowers bloom.
Illinois places: Belvidere, Brookfield, Channahon, Chicago, Des Plaines River Trail, Downers Grove, Elmhurst, Flossmoor, Geneva, Glen Ellyn, Highland Park, Hinsdale , Homewood, La Grange , Lagrange Woods, Lake Forest, Lansing, Lincolnshire, Lisle, Lombard, MacArthur Woods Forest Preserve, Marseilles, McHenry, McKinley Woods, Morton Arboretum, Naperville, Northbrook, Ogden, Ottawa, Palos Heights, River Forest , River Grove, Romeoville, Schiller Park, Thornton, Vernon Hills, Villa Park, Weaton, Western Springs, Westmont, Wonder Lake, and more.
Not sure? Ask someone in your community who lived there 17 years ago.
Why:Why do they stay underground for 17-years? The prevailing research suggests they’ve evolved a long, 17-year lifecycle to avoid predators that can sync up with their lifecycle & emergence. Why are there so many?! Research suggests that their huge numbers allow them to overwhelm predators, so enough of them will live on to breed and perpetuate the brood.
