NATURE, HISTORY AND HORTICULTURE IN FAIRFAX COUNTY
VOLUME 4, NO.2 SPRING 2004
The Otherworldly Roar of the Cicadas By Jim Pomeroy, Naturalist, Hidden Pond Nature Center
T
hey are coming. Millions of large cicadas, which have been quietly living off the juices of tree roots for the past 17 years, begin this spring to slowly work their way towards the surface of the ground. Prompted by an internal clock that can somehow record the passing of the years, the nymphal stage of Magicicada septendecem — otherwise known as the 17-year cicada — prepares to complete the final stages of their life cycle. Right on target, the last time this event occurred in Northern Virginia was 1987. According to notes from the Hidden Pond Nature Center at that time, the first cicada nymphs will crawl out of the ground on or around May 16th. About one inch long and rather stout, they will pull themselves a few feet up a tree trunk or anything else handy, and begin the process of becoming an adult. The skin which has protected them underground will split down the back and the winged adult will emerge.
The males “sing” with a kind of buzz or whirring noise to attract a mate. When performed solo, this singing is not very loud. But cicada males sing in chorus, and when millions of them get together, the result is an otherworldly noise reminiscent of the background sound effect of a science-fiction movie. An acre may have as many as one million singing cicadas, so we will be talking loudly to be heard over this din. Cicadas do not sting or bite; they do fly, though not very well. Their slow, lumbering flight carries them into buildings, cars, people, and ultimately into the six arms or legs of a receptive mate. The noise and activity will reach a peak during the first week of June, then during the weeks that follow, the activity will gradually taper off. After mating, females cut a slit into twigs 1/4 to 1/2 inch in diameter, and deposit their eggs in them. Sixteen or so eggs may be laid in one branch, with up to 400 eggs being laid by each female at 40 to 50 sites. These eggs will hatch in about six weeks. The tiny larvae will then drop to the ground and burrow down to
Sporting clear wings with bright orange veins, a large black body and striking, protruding red eyes, they are attractive mainly to each other and entomologists.
the roots of a tree. They will remain underground for the next 17 years, and may burrow as deep as 10 feet. All of this activity will leave a very visible mark upon the landscape. The incisions made for egg laying will cause the leaves at the end of the twig to turn brown. The brown clusters of leaves are known as flags, and a large tree covered with flags is a very sorry sight that will last throughout this growing season. The good news is that the damage is not permanent. Next year, this incredible natural phenomenon will be just a memory. A careful look at the twigs will reveal scars which CICADAS continued on page 8
Tips for Cicada Season Remember, cicadas don’t bite or sting. So if one gets into the house, just sweep it out the door, or sweep them off the sidewalks. Don’t spray them with pesticides. As Leon Nawojchik, manager of Ellanor C. Lawrence Park, reminds us, The cicadas are a natural phenomenon that will pass (like a thunderstorm)!
What’s inside. . . Spring Out the Door .....
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Invasive Plants ............. 4 Potomac Conservancy ... 5 Resource Management ... 6 Air Quality ..................... 7 Edith Sprouse ............... 8 Spring Jewels ................ 9 Indexed Articles ..........
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Volunteer Managers .... 11
p Fairfax County Park Authority • Fairfax, VA 22035 • 703-324-8695 • FAX 703-324-3996 • TTY 703-324-3988 • www.fairfaxcounty.gov/parks/resources