These 1 to 2 inch long aphid relatives have a black or mottled body, prominent reddish eyes, short antennae, and transparent wings, Periodical cicadas appear in late spring or early summer; the less harmful dog-day cicadas show up in mid to late summer. Male insects produce a loud buzzing “song” by vibrating membranes on the underside of the abdomen.
Target: Many trees and shrubs, especially apple, peach, oak and dogwood.
Damage: Feeding by the insects usually doesn’t do much harm, but slits made for egg-laying cause twig die-back.
Life cycle: These pests spend most of their lives below ground as nymphs, feeding on tree and lawn roots. Each brood of dog-day cicadas spends 2 to 4 years developing underground; periodical cicadas spend about 13 years below ground in the South, 17 years in the North. Once the nymphs dig their way out, they climb into trees and molt for the last time. The adults live for several weeks, during which time they mate and lay eggs in twigs. After about 2 months, the eggs hatch; the nymphs drop to the soil and tunnel down.
Notes: Since broods overlap, periodical cicadas may emerge more often than once every 13 or 17 years. Don’t plant new trees until after egg-laying; your Cooperative Extension office can tell you when a new brood is expected. Netting on young trees should have ¼-inch-diameter or smaller holes.