Cicadas 2013: Brood II Is Emerging!
UPDATED June 1, 2013
By WeatherBug Meteorologist, John Bateman
The North American cicada certainly wouldn`t win any beauty contests. With its red, beady eyes, short antennae, veined wings, and 100-decibel screech, the cicada is considered more of an ugly nuisance than a national icon. Despite this, its history is inextricably tied to that of the United States itself.
Though known to the Native Americans for generations, the cicada wasn`t documented by colonists until 1633, when the first recorded account was made in Plymouth, Massachusetts. Thomas Jefferson even correctly predicted their return to his Monticello home in 1775. Heck, that almost makes them as American as apple pie... almost.
The two main periodic cicadas that are native to the eastern U.S. are either the 13-year or the 17-year cicadas. They both remain underground, and generally out of sight, until soil temperatures about 8 inches deep warm to around 65 degrees in mid-to-late spring. They then stop feeding, emerge from the ground, molt into flying adults, and search for mates for the next two-to-four weeks.
That seems to be the easy part about understanding cicadas. When you start to talk about various "broods" and their geographic extent, that`s where things get more complicated... who knew these flying insects could be so intriguing?
It goes something like this: each returning group of cicadas is called a "brood" and given a Roman numeral. There are currently 15 broods that return on a staggered basis to the eastern U.S., and this year`s is named "Brood II." The reason for all those different broods is that the cicadas of different regions of the U.S. do not emerge in the same synchronized cycle, so they are separated into categories of where and when they appear. Also this year`s brood is not the biggest cicada boom in the U.S. - that distinction goes to "Brood X", which last appeared in 2004 and will come back again in 2021. And this is where it starts getting tricky, so for help, I enlisted Michael J. Raupp, a professor of entomology at the University of Maryland.
As for why some broods are bigger than others, and why Brood X is larger than this year`s brood, he says they`re "larger in number because Brood X is distributed over a much larger geographic region than Brood II. Where they occur, they will be just as dense - upward of a billion per square mile." [Yikes!]
In addition, each brood is more than one species of cicada (confused yet?). Dr. Raupp says, "each brood of 17-year cicadas is 3 species. Each brood of 13 year cicadas is usually 4 species."
Lastly, I thought to myself, "Is it possible for a brood of 17-year cicadas to coincidentally emerge at the same time as a brood of 13-year cicadas?" (cicada-geddon??). Well yes, it does occasionally happen but fortunately, it doesn`t happen that often. According to Dr. Raupp, the likelihood is just simple math, "It would be 13x17= 221 years." The next time Brood II will co-emerge with the 13-year Brood XIX will be in the year 2115. Ok, I can deal with that.
Now most importantly - who will see the invasion of Brood II? Generally the major I-95 corridor cities from Connecticut to the Virginia/North Carolina border, including New York City, Philadelphia, Baltimore, Washington, D.C., and Richmond, Virginia. As of June 1, there have been varied reports of cicada nymphs emerging. The most numerous reports have come from northern New Jersey, metro New York City, and central/northern Virginia. More sporadic reports have come from central Connecticut, the Hudson Valley, and the Washington to Philadelphia corridor. In fact, in some areas it's a "feast or famine" cicada scenario, where millions of bugs are swarming in one town, and hardly any are seen in another. The erractic spring weather is most likely to blame for this year's staggered arrival.
But before you get bugged-out about this invasion, here are a few facts that may help you feel better about this next cicada boom:
They are loud insects - some of the loudest on the planet - but only the males make the deafening buzzing sound to attract the females. It`s the cicada equivalent of a flashy car.
They are not locusts, and are not responsible for plagues. Flying adults don`t eat or destroy crops.
Cicadas can cause problems for young saplings or ornamental trees because the female lays her eggs in the bark of their branches. Too many cicadas trying to do the same can weaken or kill immature or diseased trees or shrubs. This can be easily remedied by covering the vegetation in cheesecloth during the time of flying adults.
And lastly, they can be beneficial. They help aerate the soil around tree roots when they emerge, they are nature`s pruning shears for weak branches, and they provide a veritable feast for dozens of other insects, mammals, and amphibians.
- Cicadas don`t bite or sting. They are not venomous or toxic either. In fact, some people actually eat them!
Perhaps this spring instead of cursing the cicada`s existence, you can marvel at the long journey these insects have made to get to their short life above ground. That is, if you can hear yourself think!
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Story Image: This is an example of a cicada taken in 2007. Shared by Bruce Marlin via Wikipedia.
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