Periodical Cicada

Rolled a number of rotten logs in Clove Lakes Park; one had 6 [Magicicadas] nymphs under it.

the ground surface and the bottom of the log. Some of the nymphs were in the top

Hello all,

So glad Brood II is close to home for me. I have a keen interest in what they do underground before emergence.

There are a couple of key observations I have made that are of interest so far.

Found my first nymphs on April 13th in Staten Island. They already have crimson eyes. The pronotal collar is pale indicating immature 5th instars. I found many exit tunnels peppering the soil near trees. No mud chimneys were seen as of yet. I uncovered some nymphs under a large board at Wolfe's Pond Park. This was a significant discovery because one of the security guards informed me that most of the park was under sea water during Super storm Sandy. This means a nymph's cell must be quite watertight! It is interesting how a nymph is adapted to move through their tunnels with speed however when put on a flat surface they are awkward.

At Blue Heron State Park I discovered a group of nymphs beneath flowerpots. Another data point and it looks like cicadas will return to Staten Island.

This past Sunday I was up in Rockland County. Thanks to John Cooley I had a datapoint nearby. I pulled over to an office building that had a large parking lot and a small stand of trees. After flipping 1 log - I discovered more nymphs! This last data point came from 1979 so I was happy to update it. I think there are M cassini here too as some nymphs were clearly smaller. It is unclear to me as to why M cassini where absent from LI but may be present in Rockland county which is located further north in latitude.

A few interesting observations - nymphs seem to love moist clay like soil. Their tunnels are usually constructed of clay and one can see the soil difference in the lining of their tunnels. Also I wonder if they feed at all as they all seem to be resting near the surface. I found one nymph underneath a big rock. He moved all the way to the end of his exit tunnel. At the deepest point there seemed to be no rootlet. therefore it appears, purely by observation, that later 5th instars may stop feeding in preparation for emergence. IT also seems crucially important that they avoid dessication. Immature nymphs are almost always moist to the touch and dessication can kill them.

During Brood XIV I kept a nymph and it emerged early in May. It loved for one month and did not feed. It resumed feeding as an adult. I know John Cooley mentioned Beamer raising nymphs inside of a potato. (Page 165 and 166 he mentions they stick their beak into the potato but they did not survive to eclose) The link to this fantastic paper is here. I really enjoy Beamer's detailed natural history observations. http://entomology.ifas.ufl.edu/walker/buzz/c700lb28.pdf

Look forward to meeting many of you during the emergence. I have 2 captive nymphs here - one has created a pseudo tunnel and is resting there. They really like that moist clay like soil.

Take care all
Elias

Update (5/9): cicadas have emerged in North Carolina, Virgina (see a photo) and Maryland (read a tweet) so far. Nymphs are active in New Jersey according to Magicicada

Deciphering the Strange Mathematics of Cicadas [Video]

Periodical cicadas are only found in the forests of the Eastern U.S. (Other, more numerous species of nonperiodical cicadas appear more often and in more locations.) The genus Magicicada includes seven species: three 17-year cicadas in the northern U.S. and four 13-year cicadas in the south. Those species are more broadly divided into three groups: decula, cassini and decim. For each group there exists a 13- and a 17-year species—for instance, the 13-year Magicicada tredecula and the 17-yearMagicicada septendecula—which, other than their lifespans and their geographic range, are almost indistinguishable. Amazingly, a single brood often contains multiple species, which grow alongside one another as nymphs and emerge from the ground in synchrony but do not interbreed.
...
Warmer ground temperatures in the south as compared to the north allow cicadas to develop more rapidly, which may account for their shorter 13-year life cycles. ... The longer the nymphal life cycle, the smaller the chance of emerging during a cold summer.” Such an effect would be strongest in colder climates, which would also explain the longer 17-year lifespans of northern Magicicada species.

Primed for Success
If a cold climate forced cicadas to develop long lifespans, the insects may have emerged from the last glacial period with a spectrum of life cycles, perhaps ranging from 12 to 20 years. Eventually two of those life cycles, 13 and 17 years, won out.

The fact that the surviving periodical cicadas have life cycles built on prime numbers may have conferred key survival advantages. ...

On the other hand, prime lifespans may relate to periodic overlaps between different cicada species, rather than overlaps between cicadas and their predators. The two prime-numbered life cycles of Magicicada ensure that asynchronous broods rarely interact where their geographic ranges overlap—a 13-year cycle and a 17-year cycle match up only once every 221 years. Those rare meetups may confer the advantage of preventing the two groups from mating and producing hybrid offspring. As Cox and Carlton wrote in 2003 , “cicadas that are hybrids of two populations with different life cycle lengths will suffer greater predation losses, as many may emerge on years before or after the main population. Cicadas with prime-numbered cycles (13 years and 17 years) will hybridize significantly less frequently than cicadas with non-prime (composite) cycles and thus will have larger emergences and a greater advantage of predator satiation.”

More recently, in a study in the Proceedings of the National Academy of Sciences (PNAS), researchers in Japan and the U.S. have deployed genetic evidence in support of a different model: that periodical cicadas simply jumped from one life cycle to the other. “They are time travelers,” says study co-author Chris Simon of the University of Connecticut. “They undergo these four-year accelerations or decelerations in their life cycles. If you go to a site where 17-year cicadas emerge, you’ll find a lot of them coming out four years early.” Some stragglers will also emerge four years late.

Given a large enough population of Magicicada, the insects emerging four years off-schedule could form a group numerous enough to survive predation, thus spinning off their own population on a new life cycle. Four years is a key offset—populations separated by less than that seem not to be able to coexist in the same location, perhaps because of fierce competition for resources between nymphs growing underground.

Once a 13-year brood had successfully spun off from a 17-year brood, or vice versa, that new population would act as a “nurse brood,” Simon and her colleagues argue, protecting invading cicada populations—provided that the invaders adapted to the new life cycle as well. “Natural selection would have promoted synchronization of invading populations to resident populations because invaders would gain protection from predation and, consequently, avoid Allee effects (failure to reproduce due to low population density),” the researchers propose. In that case, the four-year gap between the two life cycles may be more important than the fact that both are prime numbers. Says Simon: “It’s hard to say whether 13 and 17 is an accident or whether it has an advantage.”

螳螂捕蟬，黃雀在後
黃雀伺蟬 - 螳螂正要捉蟬，不知黃雀在它後面正要吃它。比喻禍事臨頭還不知道。

螓首蛾眉 - 螓：蟬的一種。螓首：額廣而方；蛾眉：眉細而長。寬寬的額頭，彎彎的眉毛。形容女子容貌美麗。

蛙鳴蟬噪 - 蛙聲和蟬聲，使人聽了厭煩。比喻拙劣的議論或文章。
蜩螗沸羹 - 蜩：蟬；螗：蟬的一種，體小，背青綠色，鳴聲清圓；沸：開水翻騰。象蟬的叫，象沸湯的翻滾。形容社會動亂。
功薄蟬翼 - 功勞象蟬的翅膀那樣微薄。形容功勞很小。常用作謙詞。
蟹匡蟬緌 - 匡：背殼；緌：蟬的針吻。比喻名是實非，兩不相干。

Question: "I have seen many living cicadas missing an abdomen. Why are they still alive?"
Answer: Most cicadas are missing abdomens because of fungal infections and predators. They keep on crawling because of the natural will to mate and survive -- off course they'll die soon and never breed because their sex organs are gone. src