Are cicadas coming to White County?

If you have been watching any of our local news, you probably have heard that Brood XIX, known as The Great Southern Brood of cicadas, is predicted to emerge in middle and southeastern Tennessee this year following a 13-year absence!  According to maps from 2011, White County is on the edge of that distribution.  Some of our neighboring counties like DeKalb, Putnam and Warren are expecting to see a large number of cicadas. So, I expect that we will see some in our communities bordering those counties. 

There is much curiosity and superstition regarding cicadas. American Indians believed that the large cicada emergence had evil significance. Early American colonists were familiar with the Biblical story of locust plagues in Egypt (they had never seen periodical cicadas until the insects suddenly appeared by the millions). The colonists immediately thought a “locust plague” was punishing them. Today, people still confuse cicadas and locusts; cicadas are commonly called locusts. The term “locust” correctly refers to certain species of grasshoppers.

The large number of cicada adults that emerge often arouses fear that crops will be destroyed. However, adult cicadas do not feed on foliage. Adults may feed on twig sap to a limited degree.

The juvenile cicadas have lived underground feeding on roots for the past 13 years.  Populations of the periodical cicada species are synchronized, so that almost all of them mature into adults in the same year. The fact that periodical cicadas remain locked together in time is made even more amazing by their extremely long-life cycles of 13 or 17 years. Large numbers of adults usually emerge in early May when the soil temperature 8 inches deep is 64 degrees Fahrenheit.  On the night of emergence, nymphs leave their burrows around sunset, locate a suitable spot on nearby vegetation, and complete their final molt to adulthood.  A mated female will make y-shaped tunnels on small twigs to lay up to 400 eggs.  This part of the branch will be damaged and foliage may turn brown. They are probably best identified by their conspicuous acoustic signals or “songs,” which the males make using special structures called tymbals, found on the abdomen. 

Cicadas are harmless. They do not bite or sting defensively, nor do they attack people. If a cicada lands on you, it is only because it finds you to be a convenient place to land - unless you happen to be using a lawnmower or weed-whacker, in which case it might be attracted by the sound.  The main damage from cicadas is expected to be on hardwood trees with small diameter twigs such as birch, redbud, oak, maple, dogwood, crabapple, elm and hackberry or on young fruit trees like apple and peach.  The best way to protect young trees is by covering them with netting with a mesh size of a quarter inch or less; do not use bird netting.  Most damage looks worse than it really is, and many twigs will heal over if trees are vigorous.  Consider this “nature’s way of pruning.”