There is a new paper out about Brood XXII, titled Evolution and Geographic Extent of a Surprising Northern Disjunct Population of 13-Year Cicada Brood XXII (Hemiptera: Cicadidae, Magicicada). I helped with the field work for this paper, traveling through Ohio and Kentucky with Roy Troutman, recording the locations of periodical cicadas.
Brood XXII, a brood of Magicicada periodical cicadas with a 13-year lifecycle, exists in Louisiana & Mississippi, and Ohio & Kentucky with no geographic connection between them (the two groups are geographically isolated). The paper discusses the similarities and differences between the two groups.
Citation for the paper:
Gene Kritsky, Roy Troutman, Dan Mozgai, Chris Simon, Stephen M Chiswell, Satoshi Kakishima, Teiji Sota, Jin Yoshimura, John R Cooley; Evolution and Geographic Extent of a Surprising Northern Disjunct Population of 13-Year Cicada Brood XXII (Hemiptera: Cicadidae, Magicicada), American Entomologist, Volume 63, Issue 4, 12 December 2017, Pages E15—E20, https://doi.org/10.1093/ae/tmx066
I’ll cut to the chase, in terms of Brood VI, I only experienced the emergence via my web browser. I planned on visiting North Carolina but rain and car troubles stood in my way. I did travel to Wisconsin to try to find legendary populations said to exist there, but I found no cicadas. I drove routes 90, 14, 12, 23, and roads in between, but I had no luck finding them. My investigation was by no means comprehensive, but I covered as much ground as I could in the two days I was there and found no periodical cicadas.
Brood X stragglers are a different story. I missed seeing the massive Virginia/Maryland area populations, but I was able to see cicadas in Princeton, and the significant emergence in the Dublin area of Ohio.
On May 20th I visited Princeton and found exuvia (shed skins/”shells”) on a pole next to where I parked my car, which was very encouraging. I headed for the Princeton Battle Monument park, a place where I saw massive numbers of cicadas in 2004. There, in 2017, I found exuvia but no adults — from 5 to as many as 200 per tree (I counted what I could see). The park was overflowing with squirrels and birds that would love to eat cicadas — I have no doubt why no stragglers survived. Blackbirds paced the lawn five abreast, like a small army systematically hunting for insect prey. During a normal emergence periodical cicadas emerge in such great numbers that many are able to get past the armies of hungry birds and rodents (this is called predator satiation). After visiting the park, I walked many side streets and found exuvia everywhere I went — not massive piles as we see during a normal, on-schedule emergence — but at least a few on every tree.
I returned on May 27th and actually found adult cicadas in Princeton. I found dozens of Magicicada cassini and a few Magicicada septendecim. There were not enough adults to form viable choruses. I doubt a few mated. I heard a single Magicicada cassini court song, so all least they were trying.
The most interesting cicada I saw was this Magicicada cassini with a mosaic pigment mutation, which caused the unusual orange marking on its abdomen. At first, I thought it was a Magicicada septendecim, but Chris Simon confirmed that it was not.
I also drove Rt 29 from Trenton to Frenchtown, across Rt 12 to Flemington, and down Rt 31 and heard no cicada populations. I visited Sourland Mountain. I visited many of the markers on Cicadas @ UCONN (formerly Magicicada.org) but found no cicadas, and certainly no viable adult populations (no singing, not enough to perpetuate a population).
North of Dublin, Ohio
On June 10th I made it to the suburbs north of Dublin, Ohio (itself north of Columbus). There I encountered a very active periodical cicada emergence. I mostly found Magicicada cassini, but I could hear Magicicada septendecim from time to time. I have little doubt that many cicadas mated and some of their progeny will survive to appear in another 14 or 17 years.
Cedar Springs, OH
When I’m mapping cicadas I try to stop at every rest stop and welcome center to look for cicadas. I found periodical cicada exuvia at a rest stop on Rt 70 hear Cedar Springs, Ohio. This was a nice find because I didn’t see any sightings in this area on the Cicadas @ UCONN (formerly Magicicada.org) map.
Indianapolis, IN, near Ft. Harrison State park
I passed through Indianapolis, IN twice on my way to and from Wisconsin. I found some exuvia on the outskirts of Ft. Harrison State Park, but nothing inside the park (weird).
This year “precursors” to Brood X are emerging or will emerge in small to large numbers in D.C., Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, Missouri, New Jersey, New York (Long Island), North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia, and West Virginia. Cicadas @ UCONN (formerly Magicicada.org) has the most up-to-date map from Brood X.
Note: because of the significant number of cicadas emerging ahead of time, this might be an acceleration event. Periodical cicada accelerations occur when a significant group of an established brood emerge in years ahead of the main brood, and sometimes the accelerated group is able to reproduce and create what is essentially a new brood. Brood VI was likely part of Brood X at one point of time1. We’ll have to see if the Brood X stragglers are able to survive predation, and reproduce in significant numbers to sustain future populations. They are certainly trying.
Don’t panic! Less that one percent of a Brood straggles. If you had 10,000 cicadas in your yard back in 2004, you can expect a less-frightening or more manageable dozens or hundreds (okay, maybe 1,000s). 🙂
Brood VI also emerges this year?
Brood VI also emerged this year in North Carolina, South Carolina and Georgia. These cicadas emerged on schedule, and are not stragglers. It is believed that Brood VI descended from Brood X through acceleration (mentioned above).
Stragglers are periodical cicadas that emerge in years before or after the brood they belong to is expected to emerge. Typically 17-year periodical cicadas emerge 4 years early (see the probability chart). While stragglers might not produce enough offspring to produce future generations, straggling is something periodical cicadas do — it is hard-wired into their DNA. The 4-year interval is also typical.
Stragglers are not a new phenomenon. William T. Davis documented accelerations of cicada populations back in the 1800s, which was reported by C.L. Marlatt in the 1898 document The Periodical Cicada. An Account Of Cicada Septendecim, Its Natural Enemies And The Means Of Preventing Its Injury.
Mr. W. T. Davis records the occurrence of scattering individuals on Staten Island in both 1890 and 1892, neither of which is a Cicada year. These may have been of accelerated or retarded individuals, but possibly represent either remnants of broods or insignificant broods not hitherto recorded.
In the case of W. T. Davis’s observations, Brood II would have emerged in 1894 in Staten Island, so 1890 would have been a 4-year straggler/processor/acceleration, and 1892 a rare 2-year acceleration.
The term “straggler” throws people off because most people are familiar with the definition of straggler that means “something that falls behind the main group”. These cicadas are clearly ahead of the main group, not falling behind. Straggle can also mean “to wander from the direct course or way” (Merriam-Webster), “to trail off from others of its kind” (Merriam-Webster). In terms of cicadas, scientists and naturalists have been using the term “straggler” for over a century, so it has stuck around. For now, don’t worry about the term, just know that it means periodical cicadas that are not emerging on schedule.
It makes sense that climate variations would trigger periodical cicadas to emerge ahead of time. Periodical cicadas take cues from the seasonal cycles of their host trees. An unusual climate event, like a hot fall or winter, might cause trees to signal cicadas that additional years have passed, and cause them to shift to emerge early. In the paper, How 17-year cicadas keep track of time, Richard Karban was able to show that you can speed up the time it takes for a periodical cicada to emerge by artificially altering the seasonal cycles of their host trees2. It’s likely that the Brood X stragglers emerging now were set on their path to emerging 4 years early not this year or the last, but many years ago.
Metropolitan areas like Washington D.C., called “HEAT ISLANDS” (read this article), can often be much hotter than surrounding rural areas due to human activity. The effects of living within a heat island may have disrupted the seasonal cycles of the cicadas’ host trees, and therefore the cicadas themselves. Localized climate change will be considered as a contributing factor to their early emergence. If we find considerably fewer stragglers in rural areas than city areas, then we could draw a conclusion that local climates are contributing to straggling.
Other than climate (in the long term), weather (in the short term), and a natural propensity to straggle or accelerate, population density is another reason why cicadas will straggle. If there is a high density of them underground, vying for limited resources, some might emerge a year or so before or after the main Brood.
1 Monte Lloyd &J o Ann White. Sympatry of Periodical Cicada Broods and the Hypothetical Four-Year Acceleration. Evolution, Vol. 30, No. 4. (Dec., 1976), pp. 786-801.
2 Richard Karban, Carrie A. Black and Steven A. Weinbaum. How 17-year cicadas keep track of time. Ecology Letters, (2000) 3: 253-256.
Final Update: I traveled to Wisconsin last week and spent a few days looking for cicadas in the southern part of the state (Madison, Baraboo, Janesville, Cedar Bluff, Dodgeville) but unfortunately I did not see or hear any. :(. So far this year though, Brood VI was spotted in GA, NC, SC, OK, OH and perhaps NY….
Brood VI (6) 17-year cicadas (“locusts”) will emerge in the spring of 2017. The main group will emerge in South Carolina, North Carolina and Georgia. Other lesser groups should emerge in Ohio & Wisconsin. And possibly other states/locations as well.
When: Generally speaking, these cicadas will begin to emerge when the soil 8" beneath the ground reaches 64 degrees Fahrenheit3. A nice, warm rain will often trigger an emergence. So, definitely May, but something might happen in April if we have a particularly hot spring.
1889 document: Dade (Trenton), Elbert (Elberton), Floyd (Rome), Habersham (Turnerville), Hill (Virgil), Paulding (Brownsville), Rabun, Spalding (Experiment), White (Tesnatee). 7
Best bet: Buncombe (Asheville), Burke, Caldwell, Henderson, McDowell, Polk, Wilkes6.
1889 document: Alexander (Mount Pisgah, Taylorsville), Bladen, Buncombe (Asheville), Burke (Morganton), Cabarrus, Caldwell (Lenoir, Hickory), Catawba (Claremont, Maiden), Henderson (Westfeldt Park, Horse Shoe), Iredell, Lincoln (Denver, Lincolnton), Macon (Franklin), McDowell (Greenlee), Moore, Montgomery, Pender (Long Creek), Polk (Columbus, Saluda, Mill Spring), Rabun (Highlands), Randolph, Rutherford, Swain (Whittier), Transylvania, Union (Waxhaw), Washington, Wilkes (Moravian Falls, Wilkesboro).7
Best bet: Oconee, Pickens6.
1889 document: Oconee (Stumphouse Mountain which is near Westminster).7
Wisconsin seems like a sure thing as well.
Best bet: Columbia, Dane, Rock, Sauk (Baraboo)5
1889 document (aside from those mentioned above: Burnett (Spooner), Columbia (Madison), Crawford (Towerville), Dane (Janesville), Fond du Lac (Ripon), Green Lake (Dartford), Marquette (Harrisville), Sauk (Baraboo), Sawyer (Hayward), Washburn (Shell Lake), Waushara (Auroraville). 7
Best bet: Hamilton (Hyde Park, Delhi, Finneytown, Green Township, Anderson). 5
I was looking through old newspapers for articles about periodical cicadas. I found an article in the Taiban Valley News from April of 1919, titled “17-Year Locust” Due This Year1. The Taiban Valley news was published out of New Mexico, which does not experience periodical cicadas aka “17-year locusts”, so I guess the story was supplied to its readers as a curiosity — just something oddball/interesting to read. The text of the article was supplied by the U.S. Department of Agriculture (possibly C.L. Marlatt himself), and the main image of the article is an illustration that appeared previously in U.S. Department of Agriculture documents and is attributable to a Miss L. Sullivan2.
97 years ago people called periodical cicadas “locusts”, just as they do today. I quote, “It has been so long miscalled by the name of locust, however, that there is no hope of divesting it of that incorrect appellation”. “No hope”! Even today, about half the people I meet call them “locusts”.
Human lifespans were a lot shorter 97 years ago
The next fact — and this startled me — is how short the average human lifespan was 97 years ago. I quote: “The fact that it appears in countless numbers one year, then is not seen again for half the average lifetime of human beings and then suddenly appears again in countless numbers”.
Half the average lifespan of human beings? Back in 1919 the average life expectancy was just 55. At most a person could expect to witness 3 emergences back then, and since babies and toddlers really don’t remember things, 2 times makes sense. Today (2016) life expectancy is around 79 years in the U.S., which means the average person will only get to see 4. I’ve seen 9, but I travel around.
Vermont still had periodical cicadas:
Back in 1919, Vermont still had periodical cicadas: “with some Isolated colonies as far northeast as upper Vermont”. Since then, they must have gone extinct.
The article talks about Brood 18 emerging in the same year as Brood 10 (note, the article does not use Roman numerals). I believe the Brood 18 the article they refer to is what we now call Brood 19 (XIX) today. The article describes Brood 18 as having a 13-year life cycle, and occurring in Alabama, Georgia, North Carolina, South Carolina and Tennessee. The only brood that matches that is Brood XIX (see the map).
If it is indeed Brood XIX, the article is likely incorrect about the coincidence of Brood XIX and X emerging in 1919. While Brood X definitely emerged in 1919, Brood XIX would emerge in the following year 2020. Interestingly enough, the now extinct Brood XI emerged in 2020 (in Connecticut).
The rest of the article is less remarkable, but still a fun read for “the most interesting insect in the world”.
David Marshall of the University of Connecticut pointed out a map of the Brood XVIII that was indeed set for emergence in 1919, which is likely what the writes of the article were citing. David points out though that this Brood XVIII was likely comprised of one-year-early emergences (stragglers) of Brood XIX, rather than an actual unique brood.
Got flagging? Flagging happens when tree branches wilt or die due to cicada egg laying, resulting in bunches of brown leaves. Don’t worry, this will not cause trees to die, unless they are small and weak trees. Flagging can actually do a tree a favor, by removing its weakest branches.
Many exuvia clinging to oak leaves. Core Arboretum, WVU.
My plan was to check out Maryland first, then head to West Virginia for a few days, and then Ohio. If weather, time and patience allowed, Virginia and Long Island, New York. Like all my periodical cicada trips I start by consulting the map on Cicadas @ UCONN (formerly Magicicada.org) to see where folks are finding cicadas. I also consult with the folks who study periodical cicadas professionally to discover their favorite hot spots and any locations of particular scientific interest. This year, the interesting spot was north-western Maryland — more on that later.
Generally speaking, you’ll see a lot of pin-drops for Magicicada cassini on the map. This is because you can hear them while driving at 70mph. You often have to stop your car and turn off the engine to hear the other species, so even though there’s lots of M. cassini on the map, there’s probably just as much M. septendecim. Generally speaking, my mapping methodology works like this: I stop and take notes when I can (usually at rest stops, parks or when I’m staying in a particular town — see Morgantown & Athens later in the article) and this is when I’ll hear M. septendecim & M. septendecula, but when I’m driving interstate highways at high speeds (with a parade of angry drivers who would rather tailgate me that use the left lane to go around me) I can only take data points for M. cassini.
What do I bring with me on a seven-day cicada road trip? Aside from clothes, road food, smartphone, and my AAA card, I bring equipment to aide my study of cicadas:
A junk computer. A decrepit laptop that I won’t care if it gets stolen.
A video camera.
A device for measuring sound level (decibels).
A notepad and pen (because technology fails).
Butterfly pavilions, which are these expandable enclosures for holding and observing insects.
Containers for holding dead specimens, and silica gel to keep them dry. Note: before you collect, make sure it is legal in the location you plan to collect. Collecting wildlife from National Parks is illegal. Collecting cicadas from a Hampton Inn parking lot is usually okay.
Suntan lotion and Bug Spray. I like insects, but ticks and mosquitos can turn cicada observation into a nightmare. Many researchers wear pyrethrum treated clothes (yes, bad for cats).
The first town I hit was Accident, Maryland (great name). There were sightings on the Cicadas @ UCONN (formerly Magicicada.org) map, and the name of the town was awesome, so I wanted to check it out. Unfortunately, I didn’t observe any cicadas there.
Route 68, West Virginia
Traveling west along Route 68, about half-way between the center of Bruceton Mills and Coopers Rock State Forest I started to hear pockets of M. cassini. I stopped at Coopers Rock, and at first, I was disappointed: I didn’t hear any cicadas from my car. Once I stopped my car and turned off the engine I could hear them: M. septendecim with their spooky sci-fi UFO chorus in the distance. It became obvious that the park had a healthy population of M. septendecim, with a smattering of M. cassini as well.
Next, I arrived at Morgantown, WV. Some twitter friends had been posting cicada photos from there, so I thought it would be a good location to set up base and make observations for a few days. The hotel I chose had an excellent population of M. septedecim and cassini around it; so much so that the staff couldn’t keep up with unwanted cicada guests that littered their doorway, trampled by oblivious human guests.
My first day there I walked around the West Virginia University campus near the hospital, stadium & iHop. The sky was overcast and it was getting late in the afternoon, but it was clear that the campus and town had an abundance of periodical cicadas, and that I made a good choice in setting up camp there. At night, in my hotel parking lot, I was able to watch cicadas emerge as nymphs as transform into adults, which is always a highlight of an emergence for me.
WVU Core Arboretum
Core Arboretum is a large botanical garden devoted to trees (“arbor”) on the WVU campus. It was an excellent place to observe cicadas. I was able to observe all three species, the tiny but LOUD M. cassini, the larger & relatively docile M. septendecim, and the rarest of the species M. septendecula. Finding M. septendecula so early in my trip was a treat. Their clockwork/tambourine sound (at least that’s what I think they sound like) gave them away.
I met entomologists Matt Berger, who has contributed many cicada photos to this site over the years, and his colleague HereBeSpiders11 (twitter name). Awesome people. I met Zachariah Fowler, the director of the arboretum as well. Another awesome person.
A white-eyed Magicicada septendecim.
I was able to check off many of my cicada checklist items in Morgantown: I found a white-eyed cicada, I saw & heard all three species, and more.
Leaving West Virginia, Entering Ohio
M. cassini were plentiful along route 79 and 50 headed west towards Athens, Ohio. Along the way, I made a few stops and heard & observed some M. septendecim as well.
Athens was another good location to stay and observe cicadas. The parks in the surrounding area had excellent cicada populations, and I had a rare chance to meet John Cooley of Cicadas @ UCONN (formerly Magicicada.org).
My first day in Athens I spent at Dow Lake in Strouds Run State Park. There I met John Cooley who was there showing a German film crew the particulars of cicada behavior. Dow Lake had a healthy mix of LOUD M. cassini and M. septendecim, but the cassini definitely dominated. The highlight for me was not a cicada, but spotting a rat snake climbing down from an acacia tree where it was no-doubt snacking on cicadas.
Sells Park in Athens was a nice place to hear VERY LOUD M. cassini choruses, well into the high 80-90db mark. So loud that I limited my time there, and left after an hour.
Hocking Hills is an amazing park north of Athens than features a spectacular above-ground cave and many acres of forest filled with cicadas. Hocking Hills had a good population of all three species, and M. septendecula were unusually easy to find. They seem to have preferred areas where deciduous trees blended with evergreens, at least in the locations I found.
Vinton Furnace Experimental Forest
A Magicicada cassini chorus from the Experimental Forest:
A Magicicada chorus with audible M. septendecula from the Experimental Forest:
Vinton Furnace Experimental Forest is a forest curated to include as much biological diversity as possible. All three periodical cicada species make up part of that diversity. M. septendcula choruses were very easy to find. The forest was thrilling to visit — aside from the biting deer flies, it was exhilarating to see or hear so many species of insects, birds, and plants in one place. Also, thrilling were the winding one-lane dirt roads; I almost died a few times thanks to wild drivers out for a pretend Finland Rally race.
Back to Maryland
After an overnight stop back in Morgantown, WV, I headed back to Maryland to prove (or disprove) that periodical cicadas were there, and if I did find them, the extent of their population. It is important to show the limits of their population as researchers (John Cooley in particular) are interested in demonstrating that the Brood V population in Ohio, Pennsylvania, West Virginia & Maryland is distinct from the population in Virginia.
I’m happy to report that I did find periodical cicadas in Maryland. The populations were mostly the relatively quieter M. septendecim — the type you really have to stop the car & turn off the engine to be certain they’re there. I did find M. cassini as well, but M. septendecim dominated. The adorably named Friendsville and Selbysport had good populations, as did the hill above the Youghiogheny river overlook rest stop on I68. South of this area, I did not hear or see cicadas on Bear Creek Road, Rt 42, Rt 219 or Rt 495. It is possible there are pockets of cicadas deep in the woods and out of earshot in those areas, but it is clear there was no great population of periodical cicadas in those areas if any at all. I spoke to a chainsaw bear sculptor in Bittinger, which is not far from where the Appalachian Plateau ends & the Ridge and Valley area starts. I showed him a photo of a periodical cicada. He said he had never seen them in his life, and nor did he see them in Accident where he went to church. He did hear about them on the news, so he was aware of them.
Pennsylvania, and home
After collecting cicada data and buying a chainsaw bear, I headed north into Pennsylvania. I stopped at a rest stop, enjoyed the last I would hear of Brood V, and headed back home.
There was an unexpected* emergence of periodical cicadas in Jim Thorpe, Pennsylvania this spring. Experts believe it is a disjunct brood related to Brood XIV. Brood XIV is found in the area, according to entomologist and Pennsylvania-based periodical cicada mapper Marten Edwards, but perhaps not in the exact same specific locations. Brood II is also in the area but on the other side of the mountain. Although this group of cicadas emerged the same year as Brood V, it probably is not related (genetically & evolutionary), but that is TBD.
The terrain of the Jim Thorpe area is comprised of mountains & valleys belonging to the Appalachian Mountain system of the Eastern United States. I observed cicadas on mountainsides and in lower valley areas. They seemed most plentiful and gregarious on the edges of the forest, preferring small, young maple trees where they gathered, sang, paired off, mated and died. Although their numbers were lesser deep in the woods, I did find exit holes and exuvia there. The most interesting discovery was finding a fully sclerotized, but dead, adult cicada within an overturned teacup left in the shade of an old tree. I discovered a few “cicada chimneys”, vertical structures made of soil surrounding exit holes, under pine trees where the cicadas seemed to need to extra hight to get above the thick layer of pine needles that littered the forest floor.
The best populations seemed to be along the Lehigh Gorge Trail from its entrance on Main Street to the Lehigh Gorge, and north, up the mountain the Lehigh Gorge Trail circumscribes, all the way to Lehigh Gorge Drive. The trees along Route 903, starting at Old Pipeline Road and heading south, were loaded with active cicadas — so many, that it was hard to avoid their flying bodies as I drove towards downtown Jim Thorpe.
If you want to see them, go this weekend (June 24-26). They were plentiful in the Lehigh Gorge area:
The population seems to be entirely made up of Magicicada septendecim. No Magicicada cassini or septendecula were found (so far).
Locals were calling them “Locusts” — sometimes I forget that’s what folks call them, but of course they’re really cicadas.
Sound files: all are Magicicada septendecim
A single call:
A Spectrogram of its call:
Multiple males calling:
An extra-weird call around 11-12 seconds:
You can here some wing flicks in this one:
*Unexpected as cicada researchers were not expecting it, but locals probably knew about it.
I found a scan of a news paper from 1880 (The Carbon advocate., March 06, 1880, Lehighton, Pa.) that mentions that “locusts” would emerge in the area in the summer. “Locust” is, of course, a common misnomer for cicada, the Carbon Advocate was the paper for the Mauch Chunk (Jim Thorpe) area, and 1880 was 8 x 17 years ago: