Cicada Mania

Dedicated to cicadas, the most amazing insects in the world.

Cicadas have three types of life cycles: annual, periodical, proto-periodical.

May 12, 2016

Cicada Straggler Alert 2016

Filed under: Magicicada | Periodical Stragglers — Dan @ 9:29 pm

Straggler Alert

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.

Map

  • Red: Brood V
  • Orange: Brood IX, 4 years early (most probable)
  • Yellow: Brood VI, 1 year early (probable)
  • Green: Brood II, 3 years late (rare, but possible)
  • Dark Green: Brood X, 5 years early (rare, but possible)

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.

May 7, 2016

Magicicada Media Faux Pas

Filed under: Chris Simon | Magicicada | Periodical — Dan @ 7:38 am

cicada invasion

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

  • “swarm” They don’t swarm—i.e. fly around in large groups.
  • “invasion” They don’t invade. They have been there the whole time.
  • “plague”
    They are not a plague like grasshoppers that come in and eat everything–they don’t chew leaves. They suck.
  • “overrun” Implies that they are imposing us when in fact we are much more of an imposition on them–clearing their trees and building Walmarts on top of them.

Here are some more funny ones…

  • “lurking underground” They are not lurking or threatening, they are innocently feeding on tree roots.
  • “hatching out of the ground” They don’t hatch out of the ground, they hatched from eggs in tree branches 17years ago.

April 30, 2016

64 Degrees Fahrenheit Eight Inches Deep

Filed under: James Edward Heath | Magicicada | Periodical — Dan @ 1:22 am

hot under the exoskeleton

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:
Gene Kristsky's Cicada Thermometer

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.

April 27, 2016

Please use the correct imagery for 17 year cicadas

Filed under: Identify | Magicicada | Periodical | Video — Dan @ 1:01 am

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:

Magicicada septendecim Brood VII 2018 09

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:
2014 Ohio Exuvia Pile by Roy Troutman

Wrong Cicadas:

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:

Tibicen linnei
(photo credit for this Neotibicen linnei).

The cicada shedding its skin on a roll of paper towel… that’s not a 17-year cicada either:

Wikipedia
(Photo Credits for the molting cicada).

Looking for people to speak at a conference or “cicadacon”?

Need a speaker for a Cicada Convention or a Periodical Cicada Event? Try these folks:

February 7, 2016

The Periodical Cicada Brood VII Revisited

Filed under: Brood VII | Magicicada | Periodical — Dan @ 9:22 pm

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.

July 12, 2015

Why do Magicicada stay underground for 13 or 17 years?

Filed under: FAQs | Life Cycle | Magicicada | Periodical — Dan @ 8:01 pm

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:

  1. How cicadas count the years as they go by.
  2. Why prime numbers? 13 and 17 are prime.
  3. Why is their life cycle so long? They are one of the longest living insects.

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.

30 Things Cicadas Do

Filed under: Eggs | FAQs | Life Cycle — Dan @ 11:59 am

One of the most frequently asked questions we receive is: “what do cicadas do“? This question is similar to the question “what is the purpose of cicadas” — the answers to both questions help people understand why these fascinating, unusual creatures exist at all.

The simplest reduction of their life cycle is:
1) They hatch from an egg.
2) They burrow underground where they will drink from plant roots for most of their lives.
3) They leave the underground and become adults.
4) The males make sounds that attract females.
5) Males & females court & mate.
6) Females lay fertilized eggs in the branches of plants, and the cycle continues.
7) They die.

The specifics of a cicada’s life cycle varies from species to species, but here is a more detailed view of what cicadas do:

From egg to 1st instar nymph:
1) Cicada nymphs hatch from eggs.

Marlatt 1907 Egg Nest Details

2) Nymphs feed on plant fluids which they access thanks to the egg-nest groove made by their mothers.

3) They leave the groove, and drift to the ground. Their descent to the ground doesn’t hurt them because they weigh so little.

4) Once on the ground, they dig into the soil until they find small rootlets, from which they will feed.

Once Underground:
5) Underground, they will tunnel/dig

6) and establish a cell

7) from where they’ll comfortably feed. Cicadas feed on the xylem sap of plants. With the help of bacteria they transform the water, minerals and amino acids found in tree fluids to the tissues of their own bodies.

8) They pee, in fact they seem to use excess plant fluid to moisten soil to help mold the walls of their cells.

9) Throughout their life underground they will move from root to root… as plant root systems change with the seasons, when roots die off, or perhaps to avoid predators.

10) Underground, a cicada may (depending on the species) go through four instars, molting three times (see an image of the four instars).

Preparing to emerge:
11) Cicadas will build a tunnel to the surface of the ground, in preparation for their emergence.

12) Cicadas often take that a step further an build a chimney/turret above ground. This often happens in shady areas or when the ground is muddy.

Once above ground:

13) They emerge from their tunnels

14) Cicadas run as fast as they can…

15) And find a surface perpendicular to the ground, hold tight, and begin to molt…

16) During the molting process (ecdysis), cicadas perform many acrobatic moves to separate themselves from their nymphal skin, including pulling their old trachea from their bodies.

17) Once outside their nymphal skin, they will inflate their wings

18) … and expand various parts of their bodies, like their heads.

19) They will change color.

20) Once their bodies are hard enough (sclerotization counts as a thing they do)…

21) They will either seek shelter, perhaps by crawling up higher along a tree trunk…

22) or if your are a Magicicada, you might stick around in the hopes that a predator will eat you.

Mating and Reproduction:

23a) If you are a Male cicada, you are going to sing… unless you belong to a species that cannot sing, in which case, you’ll move your wings in a way that will produce a sounds.
There are many types of songs: a) distress calls, b) calls to establish territory, c) calls to attract females, d) including choruses of many cicadas and e) courting calls

23b) Female cicadas, and some male cicadas, move their wings to make sounds, also in an effort to attract and engage a mate.

24) Most cicadas (aside from Magicicada during the early days of their adult lives) will try to avoid being eaten by predators.

25) They’ll fly, of course.

26) Cicadas, like Magicicada, will establish chorusing centers, which are places where the male cicadas sing together and females come to meet them.

27) Male and female cicadas will court

28) and mate

29) the female cicada will lay her eggs in grooves (ovipositing) she etches into a suitable plant stem, and we’re back to step 1.

30) The last thing cicadas do, of course, is die, and return the nutrients found in their bodies to the soil, where they will be broken down and absorbed by the plants they fed upon.

Some things cicada do not do:

Here are some things cicadas do not do:

1) They don’t seek shelter during the fall months (i.e. they don’t try to live inside your house), unlike Ladybugs or Stinkbugs.
2) They don’t sting or otherwise pass venom onto people.
3) They don’t chew plant leaves, like caterpillars or grasshoppers.
4) They don’t dump garbage in the ocean.

July 5, 2015

What are Broods?

Filed under: FAQs | Magicicada | Periodical — Dan @ 6:29 pm

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.

All Broods

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.


July 3, 2015

How Long Does a Periodical Cicada Emergence Last?

Filed under: FAQs | Magicicada | Periodical — Dan @ 2:47 pm

People often ask: “how long do cicadas last”, “how long will the cicadas be here”, or “how long do cicadas live above ground”?

People probably ask these questions, sadly, because they are tired of listening to the love songs of these cicadas. Like the saying “it is darkest before the dawn”, however, silence is typically a few weeks away.

The length of a local emergence:

The typical periodical cicada emergence will last between 6 to 8 weeks in a single location, with significant chorusing (singing) lasting about 3 to 4. Cool weather or rain can prolong an emergence.

The research paper Emergence of 13-Yr Periodical Cicadas (Cicadidae: Magicicada): Phenology, Mortality, and Predator Satiation by Kathy S. Williams, Kimberly G. Smith, and Frederick M. Stephen1 contains a wonderful study of the arc of a periodical cicada emergence. The entire emergence event takes place within 8 weeks, from the first emerged cicada to the last dead cicada (see Fig 4 in that document 1). The number of live adults reached its peak within two weeks and then began to die off in significant numbers two weeks after that, due mostly to natural causes. After that, the population of cicadas gradually dwindles due to natural deaths and predation.

Length of the chorusing:

Male cicadas will not begin chorusing at the start of an emergence, for a couple of reasons: 1) the first cicadas to emerge, which are primarily males (Fig 3 in 1), are mostly lost to consumption by predators (Fig 6 in 1), 2) Males can’t sing until their adult bodies are fully sclerotized, and 3) they need a significant number of males present before they will chorus. That said, chorusing typically begins within two weeks 2. Males will continue to chorus until enough cicadas die to no longer sustain the chorus, which is why the chorus lasts less than a month.

Length of the emergence of an entire brood:

An emergence spanning multiple states could last between 8 to 10 weeks from when the first cicadas emerge in the South to when the last cicada dies in the North. For example, Brood XXIII began appearing the second to last week of April in Mississippi, and there were likely some left in southern Illinois up until the last week of June.

References:

1 Kathy S. Williams, Kimberly G. Smith, and Frederick M. Stephen, Emergence of 13-Yr Periodical Cicadas (Cicadidae: Magicicada): Phenology, Mortality, and Predator Satiation, (1993), Ecology, Volume 74, Issue 4 (Jun., 1993), 1143-1152
2 Kathy S. Williams and Chris Simon, The Ecology, Behavior, and Evolution of Periodical Cicadas, (1995), Annu.Rev. Entomol. 40:269-95

June 27, 2015

What is Predator Satiation?

Filed under: FAQs | Magicicada | Periodical — Dan @ 9:24 pm

Why are there so many Magicicada periodical cicadas, and what does it have to do with the survival of their species? One of the answers is: Predator Satiation.

A predator is any animal that would eat a periodical cicada, i.e., birds, raccoons, squirrels, dogs, snakes, etc. Satiation, in the case of cicadas, means to supply predators with enough cicadas to eat until they are wary of eating and thus avoid them completely.

Predator satiation works like this:
1) Periodical cicadas emerge in tremendous numbers.
2) Adult cicadas are often timid, even after having sclerotized.
3) The first cicadas that emerge are eagerly consumed by predators.
4) The predators are so overwhelmed by the bounty of easily eaten cicadas, that they fill themselves to the point of disgust and exhaustion.
5) This gives the remaining cicadas a chance to escape the predators.

The first periodical cicadas are literally “fodder”, in the battle between predators and periodical cicadas, to use a war/video game analogy.

Look at this periodical cicada: it is thinking “hopefully this creature will eat me, so my siblings will live on!”

Magicicada on my finger by Dan from Cicada Mania on Vimeo.

The research paper Emergence of 13-Yr Periodical Cicadas (Cicadidae: Magicicada): Phenology, Mortality, and Predator Satiation by Kathy S. Williams, Kimberly G. Smith, and Frederick M. Stephen (Ecology, Volume 74, Issue 4 (Jun., 1993), 1143-1152) is worth reading if you are interested in this topic. They found that predation of cicadas peaks during the first few days of the emergence, and doesn’t resume in significant numbers until three weeks later (see figure 6, if you read the paper).

Unfortunately, this strategy could be detrimental to periodical cicadas in areas with dwindling populations, where there isn’t enough of them to satiate the predators completely.

This strategy might also be used by other types of periodical cicadas like the Chremistica ribhoi of India, or cicadas that emerge in large numbers like Callogaeana festiva of south-east Asia.

« Newer PostsMore »

Cicada T-shirts