Massospora cicadina, a fungus, lives in cicada larvae and passes between adults when they mate.

ECONOMIST: The 17-year cicadas are about to emerge in force

Brood X, it seems, is splitting up, and a new 13-year cicada population is evolving.

ECONOMIST: The 17-year cicadas are about to emerge in force

In a busy cicada area, it's estimated there are one-and-a-half million cicada nymphs per acre.

NPR: Roar of the Cicada

Meanwhile, Keith Clay, of Indiana University in Bloomington, is studying the idea that periodical-cicada broods are getting bigger over the decades.

ECONOMIST: The 17-year cicadas are about to emerge in force

This is the period of time that the cicada nymphs remain underground, feeding on sap from tree roots until their biological alarm-clocks go off.

ECONOMIST: The 17-year cicadas are about to emerge in force

By contrast, he found from 50 to 300 spores in each cicada female from another brood that emerged on time that year in North Carolina.

ECONOMIST: The 17-year cicadas are about to emerge in force

Keep in mind that freezing will work best for those that you are going to roast, as the consistency of the cicada may change and make them inappropriate for dishes that call for fresh cicadas.

NPR: The Cicadas Are Coming!

That means it is likely to be a busy year for Ed Johnson, director of science at the Staten Island Museum, which, with about 35, 000 specimens, said it boasts the largest cicada collection in North America.

WSJ: Bugged by Cicada Brood II? Don't Be

NPR's Melissa Block talks with Nathan Erwin, an entomologist at the Smithsonian's Museum of Natural History and Scott Harvey, an acoustical consultant with the company Polysonics, who has measured the noise levels of the cicada ruckus.

NPR: Roar of the Cicada