Cicada ManiaThis video points some of the anatomical features of a freshly molted Magicicada, like it’s tarsal claws, rostrum, clypeus, stylets, and spiracles.
The video was made with Camtasia and Pixelmator — nothing fancy; just a quick video for people experiencing molting cicadas for the first time.
The point of this article is that you should be on the alert for Magicicada periodical cicadas, no matter what year it is, and if you see or hear them, report them.
Stragglers, in terms of cicadas, are periodical cicadas that emerge in years prior to (precursors) or after their brood is expected to emerge. Most often, 17 year cicada stragglers emerge four years prior to their expected emergence date — but it is possible for periodical cicadas to emerge between 8 years earlier and 4 years later than expected. Read more about cicada stragglers.
This year (2016) Brood IX stragglers should emerge in southern West Virginia, western Virginia and the north-middle part of North Carolina that connects with western Virginia. See a map here.
Looking at the live map on Cicadas @ UCONN (formerly Magicicada.org), it is obvious that most reports come from Brood V and stragglers appear to be emerging in the Brood IX & VI areas as expected — however, there are a fair number of reports in the Brood II and X areas, which is odd.
As stated before, it is common for periodical cicadas to emerge 4 years early, but 5 years early is rare. So why Brood X be stragglers this year? That requires a little more thought.
Now we enter the realm of conjecture…
Rick Karban in the paper How 17-year cicadas keep track of time1 demonstrated how you can get cicadas to emerge earlier than expected if you alter the seasonal cycles of their host trees. Make the tree experience two cycles in one year, the cicadas will read this as “two years have passed” and they’ll emerge a year earlier. So, in the case of Brood X stragglers, it could be that their host trees experienced weather fluctuations that caused them to do something that signaled the cicadas that 2 years had passed. Add the 4 years they would likely straggle + 1 year caused by fluctuations from the host tree, and that makes for a 5 year straggler.
The other day wethertrends360 posted this on their facebook page:
Growing Degree Days tell us why the Northeast had such an early surge in plant growth but then slowed. From late February to early April temperatures were near record warm in the Northeast with the 2nd most Growing Degree Days (GDD) in 25 years (chart/map left). This allowed plants to emerge way too early and then the freezes came!
Perhaps this early surge in plant growth, then a freeze, then growth again seemed like two years had passed to some cicadas. Perhaps.
1 How 17-year cicadas keep track of time, Richard Karban, Carrie A. Black1 and Steven A. Weinbaum, Ecology Letters (2000) 3 : 253-256.
The media (news papers, bloggers, etc.) sometimes use terms to describe cicadas, and periodical cicada emergences, that range from simply incorrect to grossly hyperbolic. It is unclear if they do this to match reader expectations, to get more clicks, to write a more entertaining article, or simply because they don’t have all the facts. It bothers me when the media uses a photo or video of the wrong species, which is why I have the use the correct image page.
What media mistakes have you witnessed? Let us know in the comments.
Professor Chris Simon, of the University of Connecticut Simon Lab, is one of the premier cicada experts in the world. She provided us with her list of Magicicada Media Faux Pas (below). How many of these have you seen? Can you think of more?
Incorrect Descriptive Words
Here are some more funny ones…
Soil temperature triggers periodical cicada emergences:
James Edward Heath in his paper Thermal Synchronization of Emergence in Periodical “17-year” Cicadas (Homoptera, Cicadidae, Magicicada)1 discovered that periodical cicadas will emerge, on average, when the soil 8 inches below the ground reaches 64 degrees Fahrenheit:
Soil temperature at 20-cm [7.87 in] depth in seven locations averaged 17.89 C [64.202 F] at the time of emergence, regardless of date. Cicadas emerging from burrows had average body temperatures of 18.04 C [64.472 F]. Synchrony in emergence may be due to animals reaching a critical threshold temperature.
The soil warms their bodies and that triggers the cicadas to emerge.
A warm rain, which will seep into the earth and warm the bodies of cicadas, can trigger a “particularly intensive” emergence.
Alexander and Moore (1962) noted that emergences were particularly intensive following warm rains ( > 2 0 C ? ). I believe this suggests that the soil temperature probably was near emergence temperature and the heat transported by the water percolating into the ground warmed the soil sufficiently to raise soil temperature above the emergence threshold.
Some unanswered questions I have are: 1) how long does the temperature have to be 64°F+ – just a moment, or a certain number of hours, and 2) because we know not all cicadas emerge instantaneously, what is the maximum temperature that for certain will clear them from the soil?
This is an example of a temperature probe use to study the emergence temperature of cicadas. The probe in this picture is held by cicada researcher Gene Kritsky:
Note that males typically emerge before females and that the larger ‘decim species emerge before the smaller cassini species.
For a more modern, crowd-sourced study of this see the radiolab Cicada Tracker project.
I think I know what you’re thinking: “I don’t own a temperature probe, how can I guess when the temperature is 64°F 8” below the soil? Direct sunlight, air temperature, and rain warms the soil. Southern facing land will warm sooner than northern facing land. Land in direct sunlight will warm faster than land in shade. Rainfall on an 80°+ day will quickly do the trick, but two weeks of temps in the 70°’s should work as well. So keep an eye on the 10-day weather forecast and watch for those days in the 70s, and especially the 80s.
Minimum Flight Temperature:
Their body temperature needs to be a little warmer than that to fly. Their minimum flight temperature (MFT) is 18-21°C / 65-70°F. The temperature varies depending on the Brood and species. They’ll need a few more degrees before they’re fully functional, and start singing and mating.
So, until their bodies are about 72°F (“room temperature”) they won’t be flying, singing and mating.
Maximum voluntary tolerance temperature:
Maximum voluntary tolerance temperature (MVT) for periodical cicadas is 31-34°C / 88-93°F, again depending on Brood and species. Maximum voluntary tolerance is the point at which cicadas seek shade and when thermoregulation takes precedence over other behaviors.
See Thermal responses of periodical cicadas: within and between brood parity (Hemiptera: Cicadidae: Magicicada spp.) and Thermoregulation by Endogenous Heat Production in Two South American Grass Dwelling Cicadas (Homoptera: Cicadidae: Proarna) for more information.
1 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.
If you’re writing an article about the coming emergence of the 17-year periodical cicadas, please use the correct genus & species of cicadas.
The genus of all 17-year cicadas is Magicicada, and they are never green. The three species of 17-year cicadas are Magicicada septendecim, Magicicada cassini, and Magicicada septendecula. They’re all black with orange wings and legs and red eyes (some exceptions, but they’re never green). The four species of 13-year cicadas are Magicicada neotredecim, Magicicada tredecim, Magicicada tredecassini and Magicicada tredecula (also never green). More information about these species.
An adult Magicicada septendecim by Dan Mozgai/cicadamania.com:
An adult Magicicada septendecim by Dan Mozgai/cicadamania.com:
A newly emerged, teneral, Magicicada septendecim by Dan Mozgai/cicadamania.com:
17-year cicada video:
A singing Magicicada septendecim:
Singing Magicicada septendecim from Cicada Mania on Vimeo.
A Magicicada septendecim laying eggs:
A Magicicada septendecim up close (deceased):
Magicicada on a tree (mostly Magicicada cassini):
For the sake of cicada correctness, feel free to use them in your article. Just credit cicadamania.com.
If you are looking to license Magicicada images or HD Video, Roy Troutman has plenty of both. Reach out to him if interested. His images and video are tagged throughout the site.
Hundreds of shed cicada skins (exuvia) by Troutman:
Click/tap for a larger version:
If the cicada you use in your article is green, it isn’t a 17-year cicada. I repeat: if the cicada is green it is not a 17-year cicada.
The cicada at the top of the Wikipedia page for cicadas is not a 17-year cicada, it’s an annual cicada called Neotibicen linnei:
(photo credit for this Neotibicen linnei).
Need a speaker for a Cicada Convention or a Periodical Cicada Event? Try these folks:
Megatibicen harenosus Cole 2017
Source: ©Insect Singers | Species: M. harenosus
Family: Cicadidae
Subfamily: Cicadinae
Tribe: Cryptotympanini
Subtribe: Cryptotympanina
Genus: Megatibicen
Species: Megatibicen harenosus Cole 2017
The Internet Archive has a lot of cicada documents and information, including a growing collection of articles from journals.
Today I came across a paper about Brood VII called The Periodical Cicada Brood vii Revisited (Homoptera, Cicadidae) by L. L. Pechuman, published in 1985 in the journal Entomology News (link to the article). Brood VII will be back in New York in 2018 (not too far away) so I’m glad I found this now. Brood VII is interesting because it is geographically isolated from other broods, near the Finger Lakes area of New York. This always makes me wonder what happened that led to their isolation (glacial melting, a massive die off of host trees… who knows).
The article is a quick, but melancholy read — unfortunately Brood VII is a small and dwindling brood; it has gone extinct in many areas, and has suffered over-predation by birds in recent emergences. “Populations were just not high enough to support ‘predator satiation'”, according to L. L. Pechuman.
People who witness massive periodical cicada emergences would never think that they were a fragile insect, but they are and papers like this make that fact abundantly clear.
Both Brood XXIII and Brood IV Magicicada periodical cicadas emerged in 2015. It was my plan to go on an epic road trip, see both broods, and report and document everything. I was able to cover a lot of ground, but thanks to cool or atrocious weather, I completely missed Brood IV, and much of Brood XXIII.
The most difficult thing about planning an epic cicada vacation is timing it right. It really depends on the luck of the draw. Cicada behavior depends on the weather, and since we cannot predict the weather months, weeks, or sometimes days in advance, it is difficult to guess exactly which weeks to plan a vacation.
These cicadas like nice weather: dry, sunny, preferably in the high 70s or 80s. If it is too cold, they won’t emerge. If it is too cool, they won’t sing, making it hard to find them when traveling along the highway, because we need to hear them to find them. If the weather is absolutely abysmal, like it was in Texas this year, I’m not even going to try to look for them; I like cicadas a lot, but they aren’t worth having my car washed into a roadside ravine.
That said, I did get to hear and see a lot of Magicicadas, so I’m not complaining.
I traveled through the following states:
Mississippi: ✔ï¸Plenty of cicadas. I heard three 13-year Magicicada species in Jackson, Mississippi, in the woods behind the Mississippi Museum of Natural History.
Louisiana: ⌠I heard no cicadas. Bad/cool weather.
Texas: ⌠I saw the storm clouds, and headed back to Arkansas.
Arkansas: ⌠I heard no cicadas. More bad/cool weather.
Tennesse: âœ”ï¸ Plenty of cicadas North of Memphis.
Kentucky: ✔ï¸Plenty of cicadas in the Land Between the Lakes area.
Illinois: ✔ï¸An amazing amount of cicadas in the Giant City State Park area, including all four 13-year Magicicada species.
Indiana: âœ”ï¸ A couple exuvia/skins at a welcome center.
Note that the ⌠does not mean that cicadas did not appear in those states this year. It just means I did not see them because of weather conditions & timing.
This is a map of my cicada sightings:
Visit my 2015 Brood XXIII gallery, to see more photos like this:
Some specimens:
Some videos:
Cicadas in Giant City Park in Illinois:
Cicadas in the Land Between the Lakes Area in Kentucky:
People ask: why do periodical cicadas stay underground for 17 or 13 years?
There are three parts to this puzzle that people are interested in:
Cicadas likely don’t count like people do (“1,2,3,4…”) and you won’t find scratch marks inside the cell (where they live underground) of a Magicicada, marking off the years as they go by. However, there is a kind of counting going on, and a good paper to read on that topic is How 17-year cicadas keep track of time by Richard Karban, Carrie A. Black, and Steven A. Weinbaum. (Ecology Letters, (2000) Q : 253-256). By altering the seasonal cycles of trees they were able to make Magicicada emerge early, proving that cicadas “count” seasonal cycles, perhaps by monitoring the flow and quality of xylem sap, and not the passage of real time.
Why prime numbers, and why is the life cycle so long? This topic fascinates people. The general consensus is that the long, prime-numbered life-cycle makes it difficult for an above-ground animal predator to evolve to specifically predate them. Read Emergence of Prime Numbers as the Result of Evolutionary Strategy by Paulo R. A. Campos, Viviane M. de Oliveira, Ronaldo Giro, and Douglas S. Galva ̃o (PhysRevLett.93.098107) for more on this topic. An argument against that theory is that a fungus, Massospora cicadina, has evolved to attack periodical cicadas regardless of their life cycle. Of course, a fungus is not an animal. Maths are easy for fungi.
There are also questions about why there are 13 and 17 year life cycles, why a 4 year acceleration of a brood might occur1 and why Magicicada straggle.
1 This is a good place to start: Genetic Evidence For Assortative Mating Between 13-Year Cicadas And Sympatric”17-Year Cicadas With 13-Year Life Cycles” Provides Support For Allochronic Speciation by Chris Simon, et al, Evolution, 54(4), 2000, pp. 1326—1336.
It is important to note that when we talk about cicada broods, we are talking about the 17 & 13-year periodical Magicicada cicadas. We are not talking about Tibicen or other species.
There are 12 groups of Magicicadas with 17-year life cycles and 3 groups of Magicicadas with 13-year life cycles. Each of these groups emerge in a specific series of years, rarely overlapping (17 & 13-year groups co-emerge every 221 years, for example). Each of these groups emerge in the same geographic area their parents emerged. These groups, each assigned a specific Roman numeral, are called broods.
Gene Kritsky’s book, Periodical Cicadas: The Plague and the Puzzle, documents the history of the recognition and naming of the broods. The first person to document that different groups of periodical cicadas emerged in different years was Nathaniel Potter in 1839. Benjamin D. Walsh and Charles V. Riley devised the system for numbering the different broods in 1868, and then C. L. Marlatt sorted the 17 year broods out from the 13-year broods, giving us the system we have today.
Visit our Broods page which features a grid of the Brood names, their lifespan, when & where they’ll emerge next and links to maps.
