The Cicada Mania Blog: News, Findings, and Discoveries About Cicadas.
When a cicada sheds its nymphal skin, revealing its adult form, we call it ecdysis. You probably call it moulting, and that’s just fine.
Here are a bunch of videos of cicadas moulting:
Here is a Magicicada nymph molting (the 17-year variety) by Roy Troutman:
Magicicada nymph molting from Roy Troutman on Vimeo.
Here is Tibicen moulting by blackpawphoto (YouTube Link):
Here is a video of a Japanese cicada, the Terpnosia nigricosta, moulting by AntoSan09 (YouTube Link):
Blue cicadas. Did you know they exist? They do… at least in Australia.
What’s That Bug recently posted a photo of a blue Bladder Cicada from Australia (Cystosoma saundersii). It’s a great find. Cystosoma saundersii are typically green.
Then there is the Blue Moon blue colored morph of Cyclochila australasiae:
Photo by David Emery
Cyclochila australasiae come in many colors, but the most common color is green. “Blue Moon” is a good knickname for these cicadas because they are rare and only found, idiomatically speaking, “once in a Blue Moon”.
So, why are some cicadas blue, when their species is typically green? Here is a quote from the paper Blue, red, and yellow insects by B. G. BENNETT, Entomology Division, DSIR, Private Bag, Auckland, New Zealand:
The colours of insects are.often due to a complex mixture of pigments, some of which
are concentrated from their diet. These are carotenoids, flavonoids, and anthraquinones, and some are porphyrins made from the breakdown of plant chlorophyll. Insectoverdin is a common green pigment produced by a mixture of blue and yellow compounds. The blue is tetrapyrrole, but sometimes an anthocyanin, and the yellow is a carotenoid.
Blue + yellow = green. If the yellow is missing, you get a blue cicada. I heard that, at least in the case of the Cyclochila australasiae, the blue cicadas are typically females. Perhaps something related to genetics or behavior of the females leads to an inability to process the caroteniods ingested along with their diet (tree fluids). I’m not sure, but it’s a topic that fascinates me, so I’ll continue to look into it.
Cicada nymphs create what we call turrets or chimneys above the tunnel hole where they will eventually emerge. These chimneys are made from soil. They are a positive indication of where cicada nymphs are underground and that they will emerge soon. Cicadas seem to build chimneys in wetter, muddier areas; in dry areas they will simply make holes at the surface. The chimneys will help keep water and mud from back-filling their holes, so they can continue to breathe, take a peek out and prepare to emerge.
Magicicada Tunnel (by Les Daniels):
A cicada tunnel in Bangkok Thailand (by Santisuk Vibul):
Three Magicicada chimneys (by Roy Troutman):
Last week io9 published an article titled Why do cicadas know prime numbers? The gist of the article is that cicadas developed long, prime numbered, periodical life cycles to avoid gaining a predator that can synch up with the cicadas.
It’s an interesting read, but it’s a little thin on facts and references. Here is part of what the article is missing:
Only seven out of the hundreds of species of cicadas have 13 or 17 year life cycles, and they all belong to the genus Magicicada. Three species of cicadas have 17 year life cycles: M. septendecim, M. cassini, and M. septendecula. Four species of cicadas have 13 year life cycles: M. neotredecim, M. tredecim, M. tredecassini and M. tredecula. These are the periodical cicadas Stephen Jay Gould wrote about.
As a proof of the theory, there isn’t a wasp that specifically predates Magicicadas (the genus of cicadas with long, prime-numbered life cycles), but there is a Cicada Killer Wasp that predates Tibicen cicadas, which have shorter life cycles and emerge every year.
The book in which Stephen Jay Gould theorized about prime numbers and periodical cicadas is Ever Since Darwin: Reflections in Natural History. You can search through the book in Google Book Search, or just buy a copy (if you’re interested). I think I paid a cent for my copy (used).
Other species of cicadas also have life cycles of a prime number of years, but some do not. A species belonging to the genus Chremistica is known for four-year life cycles, which coincide with the World Cup (association football event). Okanagana rimosa is said to have a 9-year life cycle (and to be proto-periodical).
Not all cicadas are periodical cicadas; the vast majority of cicada species appear every year even though their life cycles are longer than one year.
If you want to delve deeper into the subject of periodical cicadas and prime numbers, search for the paper Evolution of Periodcity in Periodical Cicadas by Nicolas Lehmann-Ziebarth et al.
Notes:
Prof. Douglas Galvao of the State University of Campinas has written a paper titled Emergence of Prime Numbers as the Result of Evolutionary Strategy. Download his paper from Cicada Mania.
Apparently cicadas serenaded the dinosaurs! Entomologist and Mount St. Joseph professor Gene Kritsky shared the news today that cicadas lived as long as 110 million years ago during the Cretaceous period.
A quote from a press release:
New research has documented that cicadas, those noisy insects that sing during the dog days of summer, have been screaming since the time of the dinosaurs.
A fossil of the oldest definitive cicada to be discovered was described by George Poinar, Jr., Ph.D., professor of zoology at Oregon State University and Gene Kritsky, Ph.D., professor of biology, at the College of Mount St. Joseph in Cincinnati. The cicada, measuring 1.26 mm in length, was named Burmacicada protera.
Read the full Press Release on the MSJ website.
Here is a photo of the ancient Burmacicada protera cicada nymph trapped in amber. Photo credit: George Poinar, Jr., Ph.D.
It looks a lot like a modern-day first-instar cicada nymph.
Update: Here’s a video news story about Gene’s fossil find.
I need a step-up my fossil collecting hobby. It looks like there’s some places in New Jersey to find fossils. Maybe I’ll find a cicada.
The White-eyed cicada contest is complete!
I had ten “I Love Cicada” pins sitting in a bag in my office. Ten people found a white-eyed cicada, sent me a photo and won “I Love Cicadas pins”!
All white-eyed cicada photos: See their photos of a white eyed Magicicada.
Here’s the prize pins:
Most of the periodical cicadas you’ll see have red or reddish-orange eyes. A very small number, however, have white, blue, or yellow eyes. Some even have amazing multi-colored eyes. Have you seen any white eyed periodical cicadas yet? Be on the look out for them, and make sure you take a photo or video when you see one. Have a contest with your friends and family to see who can find the first white or blue eyed cicada. If you have a TV station, radio show or local website, you could have a contest for who can find the first white eyed cicada. I personally have only found one white eyed cicada (video below), so I have to guess that the odds are at least one in 10,000.
Here’s a photo of a white eyed Magicicada cicada Roy Troutman found back in 2007:
Roy took a photo of a blue eyed cicada, and I made a t-shirt from the image (I use the mug version for my morning coffee).
This is a video of white eyed cicada I recorded back in 2007:
Wenilton Luís Daltro posted some interesting cicada items on the message board, and I wanted to post them on the homepage as well.
And,
I saw quite a few articles this weekend about the discovery of bacteria that live within cicada cells that are they key to their long lives underground.
Here’s the Live Science article.
So how do cicadas gather the nutrients they need to survive, despite their low-nutrient diet? McCutcheon says that cicadas supplement their diet by maintaining complicated relationships with two species of specialized bacteria that live inside their cells. The bacteria produce essential nutrients for the cicadas that the animals neither receive from their sap diets nor produce themselves.
