Why You May Not Be Seeing Many 17-Year Brood II Cicadas

Where's the dang swarm, already?

Image
Reuters

Wasn't the East Coast supposed to be up to their soft palates in 17-year Brood II cicadas by now?

It would seem that way, given the alarm bells that have been clanging as far back as early April. Cicadas bursting from the ground like little clawed zombies, cicadas transforming trees into randy pillars of six-legged sex, cicadas carpeting the streets like squishy shag carpet, cicadas flying into our mouths and hair – in many big cities, it hasn't happened yet.

What's up with that?

I asked a few distinguished experts on cicada biology and lifestyle, and got back several explanations. The first is the unusually cold weather that's descended over the East Coast. Cicadas won't come out unless it's warm; this Memorial Day weekend, which is forecast to have nocturnal temperatures below freezing in Pennsylvania, does not classify as "warm." Look at the clouds from Friday that helped turn beach vacations into competitions to grow the biggest goosebump:

(May 24, 2013. NOAA/GOES-East)

"The strange weather may have had a detrimental effect on the brood," says Gary Hevel, a research collaborator with the Smithsonian Institution's entomology department. "I would expect that stronger numbers will occur in the following weeks as weather temperatures rise ... at least in those areas of previous occurrence, as reflected by the earlier records. Hopefully, it is not just an 'off' year for a successful emergence."

And indeed, weather models indicate a heat wave possibly gusting into the coastal Atlantic region next week. Time to get the sweep nets out, gourmands?

Geography is also playing a big role in whether or not you're likely to see a cicada. If you live in a big city like New York or Washington, D.C., your chances are already cut down because the urban terrain much less hospitable for the bugs. They can't burst through pavement, obviously, and they need a healthy tree cover to hide from predators and lay eggs.

However, there's hope in neighborhoods or parks with trees that were present during the last Brood II emergence, in 1996.

"When I lived in the heart of D.C. during the [2004 Brood X] emergence, I had very few cicadas in my neighborhood," says Dan Babbitt, manager of the insect zoo at the National Museum of Natural History. "But when you headed up to the northwest part of D.C., where there is a lot of lawn and old-growth trees, there were tons."

Many parts of the southern U.S. are indeed already in the midst of a swarming. The emergence travels like a wave over the East Coast from south to north, and it doesn't seem to have reached D.C., Philadelphia, or New York yet. Babbitt, who has a network of trained cicada spotters, says the northernmost sighting he's received was in Springfield, Virginia, which suggests that D.C.'s bugging hour could still be imminent.

Look, here's somebody's hound eating an entire shrub of them in southern Virginia (skip to 4:30 if you don't want to see the eerie transformation stuff):

Judging from history, that "wave" will not evenly paint the entire region with cicadas. "What you see depends entirely on where you are – not all places on the East Coast will expect an emergence," says John Cooley, an environmental scientist who operates the wonderful Magicicada Mapping Project.

"The periodical cicadas do tend to be quite patchy, especially in urban areas and especially towards the northern part of the general distribution," Cooley says. "In addition, many places along the East Coast are part of Brood X (emerged 2004), and the periodical cicada broods tend not to overlap (though this is not absolute)."

But there are "rip-roaring choruses going down in North Carolina and Virginia," he assures, "so what you see depends on exactly where you are and what stage of the emergence you are in."

Here's where people have spotted the bugs so far, according to Cooley's map:

And this is the latest from WNYC RadioLab's Cicada Tracker (you can report your own observations on either of these maps):

Gary Hevel can shed a little more light on potential cicada hangouts in the D.C. region. "Generally, records from 1996 (17 years ago) for Brood II indicate that Northern Virginia should be a hotspot for them, while most of Maryland and the District are somewhat of a gap," he says. "I was hoping to see them in Silver Spring where I live, but probably won't. After the D.C./Maryland gap, they do seem in the past to emerge in good numbers in Baltimore."

So the message for folks who can't wait to swat away clouds of chirruping bugs? Cross your fingers and keep waiting. In the meantime, please enjoy these 2004 photos of a cicada tormenting former President George W. Bush:

Top image: A newly emerged adult cicada peers over the top of a leaf in Arlington, Virginia, in 2004. (John Pryke/Reuters). Bottom images by Larry Downing/Reuters

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