Look for the cicadas any time

By Rozella Hardin
STAR STAFF
rhardin@starhq.com

   Get ready, Northeast Tennessee!
   Billions of those noisy, annoying cicadas are poised to make a big comeback this spring -- after more than 17 years.
   Periodical cicadas, a species of the grasshopper-like insects best known for the scratching, screeching "singing" of the males, will emerge this month, filling woodlands in all or part of more than a dozen states. Then, almost as abruptly as they arrived, they'll be gone, back underground for another 17 years.
   Keith Hart, Carter County Extension Agent, said the cicadas are commonly called locusts. From latest information he has received, the cicadas are expected to re-emerge around May 21, give or take a week.
   "That's their life cycle," said Hart. There are at least 13 broods of 17-year cicadas. This year's emergence is Brood X, the so-called "Big Brood," with a range that stretches from Georgia in the South, west through Tennessee and to isolated pockets of Missouri, north along the Ohio Valley and into Michigan, and east into New Jersey and New York.
   "This is one of those years we kind of dread," said Paris Lambdin, professor of entomology and plant pathology at the University of Tennessee. "We had an emergence a couple of years ago around Nashville, but nothing like what we expect this one will be."
   "No other periodic cicada covers so much ground. And with hundreds of them per acre in infested areas, no other periodic cicada will make so much nose," said Hart.
   Both, Hart and Lambdin agree that this year's class of cicadas will be a nuisance. "They will make plenty of noise, and adults are poor fliers that tend to bump into things, so watch for them to splash your windshield," said Lambdin.
   However as swarms go, these cicadas aren't that bad. Adults don't feed on leaves, so they won't strip the trees. "They are complex little critters. The only real damage they do is to cut a slit into small twigs, where they'll lay their eggs," Hart said.
   "The females, once mated, will lay pockets of eggs along twigs that will cause structural weakening of those twigs. The leaves out on the tips of those twigs will become brown or flagged as we call it. The greatest damage is cosmetic," Hart said. "Eventually, they may drop off and fall to the ground, the nymphs will drop off and fall to the soil, and that's where this species is for the next 17 years."
   The newly hatched adults will remain on trees for 24 hours until their bodies dry and wings harden to allow flight. The left-over skin can stay on trees for months.
   Four to five days after emerging, the males will start singing their "love song." After mating, a single female cicada lays between 400-600 eggs in small branches of trees. Favorites include oak, maple, dogwood, apple, crabapple, and ornamental plum.
   Indigenous only to the central and eastern United States, periodical cicadas then spend the bulk of their lives underground, feeding on the roots of trees and shrubs.
   "The biggest nuisance from cicadas is the noise," said Hart, who noted that not much can be done to control cicadas. "Spraying is not very effective. In fact, we don't encourage spraying. Even if spraying is done, the chemicals are probably not going to kill them. You may want to try protecting your small, young plants, especially dogweed seedlings, by covering them with cheesecloth," said Hart.
   "I do recall an instance where a grove of young dogwoods planted near a wooded area were riddled by the cicadas, and many of them died. Basically, they come and go with little appreciable damage to trees and plants," Hart exclaimed.