One of nature's weirdest, most mysterious bugs is living under Connecticut. Millions of them have been waiting the better part of two decades to stage a mass orgy of singing and sex, and we're now only a few short weeks away from their "emergence."
Magicicada Brood II, one of North America's "17-year cicada" populations, is about to dig its way out. And it could happen in your back yard.
Cicada scientists like the University of Connecticut's Chris Simon are eagerly looking forward to the last part of May and early June when these strange creatures will erupt in vast swarms. Simon and her colleagues are enthusiastically engaged in a major research effort to solve some of the puzzles surrounding these truly peculiar bugs.
Those of us "lucky" enough to be in their neighborhood when they emerge may feel a bit differently.
"Some people may be caught off guard," says Michael Singer, an associate professor of biology at Wesleyan University.
Say you're living in a nice house built after 1996 and still have some of the old trees left from the woodland that used to cover your lot. It's quite possible you never realized there were cicada nymphs sucking on your tree roots and digging through your soil. Then suddenly, one day in late May or early June, thousands and thousands of these cicadas appear.
It could freak you out. On the other hand, there's not much to worry about.
For one thing, they can only survive underground if there are the roots of trees or woody shrubs to suck on. If, in the years since their last emergence, all the trees have been cut down, there won't be any cicadas to come out. "Maybe it could be a fizzle," Singer says.
They also don't bite. They don't really do much damage to trees or flowers or gardens (if you're worried, just throw some garden netting over your bush or tree). Snakes and squirrels and fish and all sorts of other animals consider them a tasty bonanza whenever they do happen to finally leave their underground burrowing to take flight. And the adults die after only a couple of weeks, leaving their crunchy little bodies under the trees in piles to enrich the soil.
Some people even eat them. Missouri state officials have offered up recipes for "El Chirper" Tacos, "Cicada Pizza," and "Cicada-Portobello Quiche." The flip side of that coin comes from People for the Ethical Treatment of Animals, which is urging pet owners to keep their dogs on leashes and their cats inside to keep them from cicada munching – not to protect the pets, but to protect the cicadas.
Cicadas do make a lot of noise. Not surprising, really, considering that there are records of as many as 1.5 million of these cicadas crowding into a single acre and a whole mess of them are males trying to attract females by singing.
When there are lots of males singing together in a tree, it's called a "chorus." Some cicada choruses have been recorded up close at the 90-plus decibel level, about as loud as a lawn mower or a motorcycle 25 feet away.
Now, these aren't katydids or grasshoppers or locusts. They're not even the more common kinds of cicadas that emerge every other year to sing briefly in the summertime.
The 17-year variety that's about to grace us with a visit is a member of one of the more complex bug families known to science.
These are "periodical cicadas." If you're curious about complex insects, these are the babies for you. (I was going to try and simplify all this to make it more understandable, but have given up.):
-There are seven species that scientists have divided into three species groups. North America is the only place in the world where they exist.
-Each species group is divided into one 13-year species and one 17-year species, except for the "Decim" group, which is divided into two 13-year species.
-Each "brood," which is a particular group that emerges on one of these cycles, has its own Roman numeral. So there are 13 broods of the 17-year variety, and three broods of the 13-year version.
-The 13-year broods are mostly in the American south, while the 17-year ones are mostly up north.
-And here's the kicker: new DNA research by Simon and her team, working with scientists from Japan's Kyoto University, indicates these different broods can switch back and forth between 17-year cycles and 13-year cycles.
"And they've done it multiple times," says Simon, sounding like a proud parent of some championship Little League squad. A professor of ecology and evolutionary biology at UConn, Simon is understandably fascinated by these cicada critters.
In a paper recently published by the Proceedings of the National Academy of Sciences, the cicada researchers argue this bug represents "one of the most spectacular life history and population phenomena in nature."
One of the biggest mysteries surrounding these colorful (black bodies, red eyes, orange wing veins) little varmints is why they ever evolved this whole 13-year/17-year mating and egg-laying shtick.
For a long time, the best available theory was that it was designed to screw up predators. No insect eater, scientists suggested, was going to wait for such long periods for a super cicada feast, thus giving these periodic cicadas a better chance at making little cicadas.
"That was the conventional wisdom for a long time," Singer says. "But for people who study it, they weren't entirely satisfied with that explanation."
The DNA study that Simon was involved with came up with a different possible explanation.
"We think it's related to climate," she says. "If a growing season isn't long enough, they can't complete their development in 13 years." Needing some more time, the brood simply switches to the longer cycle.
These changes in the 13-year and 17-year cycles have happened at least four times in the last 10,000 years, according to Simon.
The conclusion of that published study was that these switches were "closely associated with global climatic fluctuations and shorter growing seasons in the north versus the south."
The problem for these guys is that, for a brood to make the switch successfully, a whole bunch have to do it at the same time — they apparently really like big-group sex parties. "The ones that switch don't always survive," Simon explains.
Exactly how the cicadas regulate these life-cycle switcheroos is still a puzzle needing additional study, the researchers pointed out.
There is one other phenomenon associated with these periodic explosions of cicadas: a minor media frenzy.
The other day, a television crew took one of Simon's colleagues out to a park, presumably to talk about the cicadas that hadn't yet emerged, in a place where they may or may not ever show up.
"I don't know what they thought they were going to see," shrugged Simon. "It'll be a while before [the Brood II cicadas] come out."