The Fate of Connecticut Cicadas, One Year Later

Jun 10, 2014

Connecticut lies at the upper reaches of Brood II -- a massive underground city of cicadas.

Last June, Connecticut played host to an emergence of periodical 17-year cicadas. For many, promises of bug swarms covering neighborhoods never came to pass.

For others, in places like Meriden and North Branford, millions of cicadas did take over, lining roads, trees, and mailboxes. One year later, I met up with an entomologist to see what those bugs have left behind.

John Cooley, a scientist at the University of Connecticut, studies cicadas. Last year, he spent a lot of time in his car, driving over 2,500 miles tracking cicadas in the state. "At the end, you're just done driving," Cooley said. "I don't want to drive anymore! I'm sick of this car. I'm sick of these roads!"

We were back in his car, returning to a spot in Meriden that was overrun with the bugs last year.

Connecticut lies at the upper reaches of Brood II -- a massive underground city of cicadas, which come out every 17 years to mate, lay eggs, and die. "Here we are, a year later," Cooley said, "and most people think the cicadas are gone away and disappeared, but actually they're still around. They're underground."

2013 records of Brood II (green circles) superimposed on late 19ths century entomologist Charles Marlatt's map of the same brood (gray circles and question marks).
Credit Cooley, J. R., C. Simon, C. Maier, J. Yoshimura, M. D. Edwards, C. W. Holliday, D. C. Marshall, R. L. Sanders, M. L. Neckermann, G. J. Bunker, and J. D. Zyla. / In prep. The distribution of periodical cicada (Magicicada) Brood II in 2013, with surprising disjunct populations (Hemiptera: Cicadidae: Magicicada). The American Entomologist.

Cooley logs cicada sightings via GPS, driving around the country creating detailed maps that track emergences. He called up his logs from last year.

Cooley's GPS blinked red in front of a large oak tree outside a house near Hubbard Park.

At first, we didn't see much, but as we walked toward the tree, we saw it was covered in tiny little marks, relics of last year's emergence. "These are the scars left on the trees by the egg-laying," Cooley said. "This oak had a pretty good year last year, so it did a lot of growing after the eggs had hatched. You can see it's a slit in the bark, and the wood is poking up in there. The female excavates those little dual-pronged structures into the small twigs, and lays rows of eggs in those two slits."

A cicada nest rift. Cooley said the bugs can lay up to 600 eggs in a single rift, and that the scars don't hurt the tree.
Credit Patrick Skahill / WNPR

Cooley said the bugs didn't harm the tree. "She'll lay her eggs, about 600 of them," he said. "Then, probably July of last year, those eggs hatched, and the nymphs fell into the ground."

Once the bugs have burrowed into the ground, they begin feeding. "If you imagine looking at the world with X-Ray goggles, you can imagine a lot of things," Cooley said."If you looked down at this soil, you'd see a mass of roots ... so they're down there, feeding on something, and they're taking 17 years to do it."

Now that Cooley has had time to review last year's data, he said there were lots of surprises. Scientists even discovered a new species of cicada in Connecticutmagicicada septendecula. Cooley said all his bug tracking helps scientists learn about species distribution -- things like how nature is responding in real time to climate change.

A bumper sticker on the back of Cooley's car. He's traveled thousands of miles around the country tracking cicada emergences and logging them at magicicada.org.
Credit Patrick Skahill / WNPR

Cooley said some unlucky "straggler" cicadas may emerge this year, because bugs that miss the 17-year emergence tend to miss in increments of one to four years. No one is sure why. "Somewhere here in the state of Connecticut," Cooley said, "there's a handful of cicadas out this year. It's just a question of finding them."

But Co0oley won't be looking. Instead, he'll travel this month to the midwest, driving 10,000 miles as he tracks the emergence of another cicada brood in Iowa and northwestern Illinois.