United States. Department of Agriculture

“ One application applied when egg-laying begins will afford protection for 1 to 3 weeks, depending on the degree of infestation. Repeat applications only after reinfestation is evident. To prepare a Sevin spray, mix 2 pounds of a 50-percent wettable powder with 100 gallons of water.
TEPP acts only on direct contact with the insect. It does not affect insects that come to the tree after the « 8 » spray has dried, thus orchards close to woodlands have to be sprayed almost daily. Orchards further from heavy infestations can be protected reasonably well by three or four applications a week apart. ”

“ Orchard trees 1 or 2 years old may be protected by covering them with open-weave cloth, such as heavy cheese-cloth, netting, tobacco shade cloth, or the cloth used to cover tobacco seed-beds in the South. ”

“ The adults live 5 or 6 weeks.
Not all cicadas pass through all the stages of development. Many eggs do not hatch. Some nymphs never get established on roots, and some die while trying to shed their nymphal skins.
When They Appear
Latitude and elevation produce the conditions that determine the date on which cicadas come out of the ground. In some southern areas the period of emergence begins in the last week of April. In some northern areas it begins in the last week of May. Between these early and late extremes, periods of emergence occur elsewhere. ”

“ The cicada is now an adult, but is soft and white. It hardens and becomes darker. In a few hours it is fully mature.
The insects mate within a week after becoming adults. A few days after mating, the females lay eggs. ”