June 10, 2013 at 6:50 PM ET
A little more than a month after this spring's great cicada outbreak began, the stink of dead insects is wafting through the air in North Carolina — even as the bugs' 17-year life cycle is reaching its prime farther up the East Coast.
"It's pretty much over, I'm afraid," said Tommy Joseph, a technology manager at the Greensboro Public Library who was among the first to report cicada sightings in North Carolina in early May.
Billions of periodical cicadas have been rising up from the ground over the past few weeks, after spending the past 17 years underground as immature nymphs. The insects emerge from burrows, shed the shells of their childhood, crawl up trees and buildings (and even legs), take wing and look for mates.
Scientists suspect that so many cicadas emerge at once as part of an evolutionary strategy to overwhelm their predators with sheer numbers. This year's breed is known as Brood II. Other broods of 17-year and 13-year cicadas take their turns in different years, and still other types of cicadas emerge every year.
Buzzing in the North
Brood II has a patchy geographical distribution, extending along the East Coast from North Carolina (and a bit of Georgia) to New York (and a bit of Connecticut). The buzz of the brood's mating call can create a 90-decibel hum — which is about as loud as power tools and lawnmowers. (And in fact, those mechanical sounds have been said to attract the bugs.) In the space of just a few weeks, the cicadas couple up, lay their eggs and die.
In temporal terms, the cicada outbreak is like a wave, moving northward in May and June as the spring weather warms. John Cooley, an entomologist at the University of Connecticut, said Monday that the outbreak has reached its peak in the north. "They're pretty much out in all the places they're going to be out," he told NBC News.
The current hot spots include northern New Jersey as well as Staten Island and the Hudson Valley in New York. For a nice cicada drive, Cooley recommended Routes 9G and 9H, heading up the Hudson Valley. Throngs of cicadas have been sighted on Bard College's campus, he said.
Somber in the South
The story is more somber down south: On the Entomology-Cicadidae discussion forum, Joseph reported that "the stench of death is in the air" in Greensboro. The smell has been "pretty bad over the past week or so," he told NBC News.
"I haven't actually seen a live one in probably two and a half days," Joseph said Monday. "The remains are not quite as prominent as you would have thought. We find wings here and pieces of 'em there, but it's not like giant piles of dead ones."
One potential reason for the dearth of dead cicadas is the fact that they're considered tasty by dogs, squirrels and other species looking for a snack. Even humans are giving the bugs a try. The taste of cooked cicadas has been compared to shrimp, or asparagus, or nuts, or popcorn.
In her "Cicada-Licious" cookbook, entomologist Jenna Jadin says it's best to scoop up the bugs by the bagful when they're newly hatched. She has come up with recipes for cupcakes, casseroles, cocktails and candies that incorporate cicadas.
Is it safe? "I don't think the average person who wants to go out and enjoy the cicada emergency by having a meal of cicadas or two [has] anything to worry about," Jadin told National Geographic. But you'd better hurry: The fresh-cicada season is clearly nearing its end.
To keep tabs on the progress of "Swarmageddon," check out Cooley's Magicicada.org website, Dan Mozgai's Cicada Mania blog and Radiolab's Cicada Tracker, as well as the Twitter hashtags #BroodII and #cicadas. If you see something, say something ... in a comment below.
Previous chapters in the cicada saga:
To sample the lighter side of Swarmageddon, check out this New Yorker essay on missed cicada conections.
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the NBC News Science Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with NBCNews.com's stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.