Invasion of the magicicada
JASMIN K. WILLIAMS Amsterdam News Staff | 5/23/2013, 4:29 p.m.
Get ready for Swarmaggedon. From North Carolina to Connecticut, the East Coast is bracing itself for one of Mother Nature's most spectacular events. The cicadas are here. They may gross you out with their big, red eyes, orange wings and crunchy, black bodies, but without stingers or teeth, they are relatively harmless. It's a good thing too, because hundreds of millions of them will emerge, outnumbering us humans by as many as 600 to one.
There are more than 2,500 species of cicadas, and most come and go yearly with barely a notice, but the ones we're expecting any day now are the magicicada, or periodical cicadas. There are 15 different broods of periodical cicadas, which emerge in different parts of the United States and in varying masses on a 17-year or 13-year timetable, depending on the brood. We're bracing for the large Brood II variety, which are the offspring of the 1996 cicadas. These insects were born when President Bill Clinton was in office.
Cicadas start out as eggs about the size of a grain of rice. The female can lay as many as 600 of them. Once they hatch, the grubs begin to suck on the branch they hatched on before falling to Earth, where they begin digging in search of a tree root. They become nymphs, a stage that they will remain in for all of their underground lives.
Magicicadas always emerge in spring and early summer, April through June. Some unfortunate stragglers might appear a few years early or a few years late, but these quickly fall prey to predators. Wingless nymphs live completely underground, surviving solely on xylem of living trees and the fat stored in their bodies.
Magicicadas go through several stages of development. Then, for reasons that scientists still don't completely understand, once the temperature eight inches below the ground reaches 64 degrees, the nymphs begin bubbling out from the Earth and begin climbing trees, shrubs and everything else. After about a week, they'll shed their exoskeletons and emerge as loud, red-eyed, obnoxious, flying adults with one thing on their minds: mating.
The raucous courtship ritual lasts from four to six weeks and can be summed up in one word: LOUD. The males have plates on their abdomens to produce their courtship songs while females click their wings together to signal approval. But their singing, if you call it that, can reach up to 94 decibels, as loud as a rock concert and loud enough to drown out airplanes.
Trees are critical to the cicada life cycle. While cicadas are parasites, feeding on the fluids from trees, they don't do mass harm the way locusts do. It would not be in the cicadas' best interest to destroy the trees because they depend on them for their survival. They crawl up into the trees once they emerge and develop into adults, mating and laying eggs in the trees. Saplings and weak branches may see a little damage.
Cicadas emerge in such spectacular numbers due to a strategy called "predator satiation." This ensures that there will be plenty of them to satisfy the appetites of their predators, both above and below ground, while also making sure that there are enough of them left to produce the next generation. Pesticides, extreme weather, tree removal and construction are man-made threats. Besides birds, other insects, wildlife and humans who make a meal of them, magicicadas also fall victim to a pathogenic fungus called Massospora cicadina. This fungus lives in the soil and infects the nymphs as they leave the ground. It grows in the abdomen and, in worst cases, causes the abdomen to fall off. The fungus discharges spores and infects other cicadas as they mate. Males are left unable to mate; females can mate but can't produce eggs. The fungus then goes into a resting phase back in the ground where it will remain dormant, waiting to infect the next brood of cicadas. The survival-by-large-numbers strategy works because cicadas are the longest-living insects known.