“Summertime and the Livin’ is…”George Gershwin
Get set for the largest disco on the East Coast to let loose in the trees above your yard this month. The biggest boy band on earth is cranking its amp to over 100 decibels and will be singing at the top of their boom boxes all day long. Brood X is ready to party like it’s 2004, which is the last time we saw these red-eyed revelers. The 17-year periodic cicadas are here!
What are cicadas? And why are we so interested in them? Cicadas are not locusts. They are harmless insects who will not bite or sting you and will not do fatal harm to your trees. Like all insects, cicadas have three body parts (head, thorax and abdomen), six legs, two antennae and, unlike the annual cicadas, two beady, red eyes.
Brood X (read: “brood ten”) is one of many broods of periodic cicadas who have spent years underground as nymphs. There are also annual cicadas in our yards which emerge every year. Cicadas are 3,000 species in the order Hemiptera, or true bugs, all 80,000 of which have sucking mouth parts. And cicadas truly do suck: after hatching from an egg laid in a slit on tree bark, the nymph drops to the ground and burrows under the soil to find grass roots to suck on. While growing and molting five times, they burrow further under ground, typically 9 or 10 feet under, to find tree roots on which to attach with their mouthparts. They spend the next 17 years sucking sap from these tree roots and burrowing in the soil. They are the longest-lived insect on earth.
Brood X is made up of three species of cicada in the (….no joke…) Magicicada genus. They are the “Pharaoh” Magicicada septendicicum, whose nickname comes from its call, “Phaaaaaaroooooh”, Magicicada cassinii, and Magicicada septendecula. They look pretty much the same but their calls are all different. All are large, between 2.5 and 3.5 inches long, brownish-green, and have beautiful clear wings with orange veins.
Cicada Life Cycle Art Gallery, Illustrations & Tattoo Design by Margaret Wohler
No one knows how the nymphs are signaled when to emerge, but after spending a dark, lonely 17 years underground, they dig to the surface when the soil warms. They crawl out to cling to surfaces like tree bark, telephone poles, sidewalks or anywhere, then split their exoskeleton down the back for the adult cicada to emerge, soft-bodied and vulnerable. The adult cicada pumps blood into his crumpled wings to stiffen them as his exoskeleton hardens and darkens. Then the party begins….
Trillions of Brood X cicadas will emerge this week. They will take five days to fully harden which is important for their singing. Cicadas make noise by pulling on the ridged segments of their “singing” organ called a Tymbal, located on their hollow abdomen, which must be hardened enough to vibrate and resonate. The males emerge first and gather to sing in the sunny treetops in groups called choruses. Their screeching songs drive the ladies wild, as the female cicadas approach the males and flirtatiously flick and click their wings in rhythm with the males’ songs. The couples mate over another five days before the females make slits in tree twigs to lay up to 600 eggs. The males then start to die and the party winds down as the life cycle starts all over again on its 17-year journey.
Like all big disco parties, there are some shady characters attracted to the fun. The weirdest is the parasitic fungus,Massospora circadian. This fungus attacks the male cicada’s abdomen and brain, causing the male cicada to act like a saucy gal, and damaging his ability to mate normally. The male cicada’s abdomen becomes full of white fungal spores while his zombie brain causes him to act like a flirty female, flicking and clicking his wings, in response to other males’ songs. These duped males then try to mate with the zombie infected males and pick up the fungal spores, causing them to become infected, too. It’s a wild party up there in the trees!
As the trillions of adult cicadas emerge, local animals gorge themselves on them in a tremendous suburban buffet of insect protein. Cicadas have no defenses except their large numbers. They emerge in such huge, specifically-timed broods as a survival strategy: to exhaust the appetites of their predators in the hope that a few adults will survive long enough to mate and lay eggs before dying. The strategy, like all crazy parties, seems like a fantastic waste of life and energy but evolved behavior does not follow polite or reasonable rules other than to do what works to advance the species. Periodic cicadas have been around for almost 200 million years so the biggest party on earth seems to be a practical way for them both to survive and engage in an epic blow-out to remember.
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Author’s Note: Margaret Wohler is a local artist & naturalist at Huntley Meadows Park in Fairfax, Virginia.
The Rev. Joani Peacock, Editor for Emmanuel Voices: A Parish Blog