Source: Jonathan Larson, entomology extension associate 

Kentucky will be the epicenter for the emergence of Brood XIV of 17-year periodical cicadas this spring. Periodical cicadas have appeared in Western Kentucky counties over the past few years, but the largest emergence area for 2025 will occur across most of Central and Eastern Kentucky. 

While these time-keeping, red-eyed insects are not harmful to humans or pets, their egg-laying habits could damage the branches of young trees and shrubs. Tree netting is the most effective, non-invasive way to protect your landscaping and fruit trees.  

The 17-year periodical cicadas are expected to emerge from the soil to molt into their flying, adult form in late April to early May, when the soil warms to the mid-60s. Periodical cicadas emerge much earlier than annual cicadas and in greater numbers.  

Cicadas do not bite or sting, and the feeding habits of the adults do not damage plants. Some may find the abundance of molted shells and loud, near deafening singing a nuisance, while others will enjoy this pageantry of nature. The periodical cicadas’ choral song, however, is a cue to protect landscaping and orchards.  

Female cicadas will lay their eggs into the new, lower branches of several species after mating: apple, arborvitae, ash, beech, berry and grape vines, crab apple, cherry, dogwood, hickory, holly, maple, lilacs, magnolia, oak, peach, pear, rose bushes, spirea and willows are the most likely targets. 

The cicada’s ovipositor is long and sharp, and they will inject 200 to 600 eggs into the stem tissue. This “flagging” may cause the tender branches to snap. The fallen branch makes for a much shorter journey for the hatching nymphs from egg to soil but is not beneficial for the growing tree. Once the eggs hatch, the nymphs will feed on root sap, and a heavy population of nymphs in the soil may also impact the tree’s root system. 

While using insecticides may be less costly, the safest and most effective way to prevent tree and shrub damage is by using cicada netting, which prevents females from laying their eggs. Netting is suggested for use on new and smaller trees and should be installed when the cicadas begin to sing, about mid-May for most of the area. Trees that are established in the landscape—too tall to net for most people— will grow throughout the egg-laying period. 

More information can be found at the University of Kentucky Martin-Gatton College of Agriculture, Food and Environment publication here: https://entomology.ca.uky.edu/ef446.   

You can also contact your local (COUNTY NAME) Extension office for more information on protecting trees and shrubs from cicadas.  

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