This spring when the soil temperature reaches 67 degrees a red-eyed swarm of critters that emerges from underground every 13 years will fill the air over much of Middle Tennessee with their ear-splitting mating calls. Often confused with locusts, scientists call them Periodical Cicadas, Brood XIX. These insects are not poisonous. They don't transmit disease. They cannot sting and adult cicadas live for only four to five weeks. The adults do not feed on foliage, but the females can cause damage to young trees.
The female cicada has a knife-like ovipositor that she uses to slit twigs before she lays eggs inside the slits. Once hatched the young cicadas fall and burrow underground. Each female can lay a total of 400 to 600 eggs and the multiple punctures pose a threat to young trees by causing twig tips to wilt and die. The slits also provide a point of entry for other insects to invade the tree. Apple, pear, dogwood, oak and hickory are the favorite hosts, but you can see the puncture marks on many tree species. Insecticides have not proven effective for preventing cicada damage. When feasible, small, valuable shrubs and trees may be covered with a loose woven or spun fabric such as cheesecloth or floating row cover for protection while cicadas are present. This covering should be secured at the trunk to prevent infiltration. Delay pruning young trees until after cicada emergence so damaged branches can be removed. If pruning is done before eggs hatch, burn the damaged twigs.
