Cicadas and locusts are larger insects with wings and big eyes that live in the groun
d for a year to 7 or even 17 years before they come out again. Some summer cicadas appear regularly each summer, and do not do much damage to plants.
The damage by the periodical cicada is done when the adult females climb up trees and shrubs and create slits in the bark of young stems to create pockets for the deposit of eggs. The eggs hatch, and the larvae drop or crawl back down the tree or shrub and burrow into the soil for the next dormant period.
The damage is seldom fatal to the plant immediately, but the scarring to the branches can be unsightly, and can weaken the branches to the effects of wind or snow load in subsequent years.
The only effective deterrant is to cloak the plant with a physical barrier when the cicadas are active. (A messy, but sometimes effective barrier on the trees can be created by liberally coating trees with Tanglefoot, which traps the cicadas in a sticky substance, preventing them from climbing up the tree to lay their eggs.)
