“The periodical cicada four-year acceleration hypothesis revisited and the polyphyletic nature of Brood V, including an updated crowd-source enhanced map (Hemiptera: Cicadidae: Magicicada)”
Authors: John R. Cooley, Nidia Arguedas, Elias Bonaros, Gerry Bunker, Stephen M. Chiswell, Annette DeGiovine, Marten Edwards, Diane Hassanieh, Diler Haji, John Knox, Gene Kritsky, Carolyn Mills, Dan Mozgai, Roy Troutman, John Zyla, Hiroki Hasegawa, Teiji Sota, Jin Yoshimura, and Chris Simon.
The periodical cicadas of North America (Magicicada spp.) are well-known for their long life cycles of 13 and 17 years and their mass synchronized emergences. Although periodical cicada life cycles are relatively strict, the biogeographic patterns of periodical cicada broods, or year-classes, indicate that they must undergo some degree of life cycle switching. We present a new map of periodical cicada Brood V, which emerged in 2016, and demonstrate that it consists of at least four distinct parts that span an area in the United States stretching from Ohio to Long Island. We discuss mtDNA haplotype variation in this brood in relation to other periodical cicada broods, noting that different parts of this brood appear to have different origins. We use this information to refine a hypothesis for the formation of periodical cicada broods by 1- and 4-year life cycle jumps.
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A new paper has been published titled A molecular phylogeny of the cicadas (Hemiptera: Cicadidae) with a review of tribe and subfamily classification by David C. Marshall, Max Moulds, Kathy B. R. Hill, Benjamin W. Price, Elizabeth J. Wade, Christopher L. Owen, Geert Goemans, Kiran Marathe, Vivek Sarkar, John R. Cooley, Allen F. Sanborn, Krushnamegh Kunte, Martin H. Villet, Chris Simon.
The paper was published in Vol 4424, No 1 of Zootaxa. Link to paper.
In a nutshell: These researchers compared the DNA of a variety of cicadas to determine how they are related evolutionarily and how they should be organized in terms of tribes and sub-families.
A molecular phylogeny and a review of family-group classification are presented for 137 species (ca. 125 genera) of the insect family Cicadidae, the true cicadas, plus two species of hairy cicadas (Tettigarctidae) and two outgroup species from Cercopidae. Five genes, two of them mitochondrial, comprise the 4992 base-pair molecular dataset. Maximum-likelihood and Bayesian phylogenetic results are shown, including analyses to address potential base composition bias. Tettigarcta is confirmed as the sister-clade of the Cicadidae and support is found for three subfamilies identified in an earlier morpho- logical cladistic analysis. A set of paraphyletic deep-level clades formed by African genera are together named as Tettigo- myiinae n. stat. Taxonomic reassignments of genera and tribes are made where morphological examination confirms incorrect placements suggested by the molecular tree, and 11 new tribes are defined (Arenopsaltriini n. tribe, Durangonini n. tribe, Katoini n. tribe, Lacetasini n. tribe, Macrotristriini n. tribe, Malagasiini n. tribe, Nelcyndanini n. tribe, Pagi- phorini n. tribe, Pictilini n. tribe, Psaltodini n. tribe, and Selymbriini n. tribe). Tribe Tacuini n. syn. is synonymized with Cryptotympanini, and Tryellina n. syn. is synonymized with an expanded Tribe Lamotialnini. Tribe Hyantiini n. syn. is synonymized with Fidicinini. Tribe Sinosenini is transferred to Cicadinae from Cicadettinae, Cicadatrini is moved to Ci- cadettinae from Cicadinae, and Ydiellini and Tettigomyiini are transferred to Tettigomyiinae n. stat from Cicadettinae. While the subfamily Cicadinae, historically defined by the presence of timbal covers, is weakly supported in the molecular tree, high taxonomic rank is not supported for several earlier clades based on unique morphology associated with sound production.
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A new paper, A specialized fungal parasite (Massospora cicadina) hijacks the sexual signals of periodical cicadas (Hemiptera: Cicadidae: Magicicada), has been published by John R. Cooley, David C. Marshall & Kathy B. R. Hill, in Scientific Reports 8, Article number: 1432 (2018).
In a nutshell: the fungus infects males and causes them to exactly mimic the mating behavior of female cicadas, thus infected males end up spreading the fungus to uninfected males.
Male periodical cicadas (Magicicada spp.) infected with conidiospore-producing (“Stage I”) infections of the entomopathogenic fungus Massospora cicadina exhibit precisely timed wing-flick signaling behavior normally seen only in sexually receptive female cicadas. Male wing-flicks attract copulation attempts from conspecific males in the chorus; close contact apparently spreads the infective conidiospores. In contrast, males with “Stage II” infections that produce resting spores that wait for the next cicada generation do not produce female-specific signals. We propose that these complex fungus-induced behavioral changes, which resemble apparently independently derived changes in other cicada-Massospora systems, represent a fungus “extended phenotype” that hijacks cicadas, turning them into vehicles for fungus transmission at the expense of the cicadas’ own interests.
And now, because I need an image for the post: a meme:
Cicadas, when infected, are called “salt shakers of doom”. Add that to the meme “Salt Bae”, and the image makes sense.
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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
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 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 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 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.