The 2024 cicada invasion: How to save your trees and shrubs from damage

The cicadas are coming. Are your trees and shrubs ready for the invasion?

The emerging Brood XII and Brood XIX cicadas love to target deciduous trees, or those that with leaves that change colors and drop in the fall. No need to worry about those evergreen trees, known as coniferous trees, which can maintain their leaves throughout the year. Cicadas don't like them.

Cicadas feed on more than 250 types of tree species, but they prefer sapling trees, such as ornamental shrubs and bramble fruits such as raspberries and blackberries. All are in harm's way, along with maples, cherries and dogwoods.

Where will the cicadas emerge? Map shows locations around the U.S.

What causes 'flagging' in trees?

In years when periodical cicadas emerge, tree flagging, or patches of withered and wilted leaves, can be widespread and dramatic.

Female cicadas can damage several varieties of trees and shrubs. They use their saw-like appendage, known as the ovipositor, to lay their eggs on branches. The weakened twigs can be broken by the wind and fall to the ground or dangle from the tree. By June and July, leaves and twigs can litter the ground.

"When the females lay their eggs, it's almost like a natural pruning," says Dr. Gene Kritsky, dean of the School of Behavioral and Natural Sciences at Cincinnati's Mount St. Joseph University.

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Hold off on planting any new trees

Taking preventive measures is the best defense against cicadas for young trees. If you live in an area affected by the emerging Brood XII or Brood XIX, you might want to postpone planting young trees until fall or next year.

Install protective tree netting

Cover trees, bushes and shrubs with netting with openings of a half-inch or less to block the cicadas from getting to plants. A fine mesh bug netting also can be used for specific trees or plants. Avoid using bird netting because its openings are typically too large to stop cicadas from crawling through.

To stop cicadas from crawling up under the netting, make sure the bottom of the bag or netting is securely tied to the trunk. You can remove the netting, when the adult periodical cicadas have died off, usually around the end of June.

Put away the chemical insecticides for cicadas

Avoid using chemical insecticides for cicadas. Chemical insecticides are less effective than netting: In a 2021 study, trees treated with pesticides experienced significantly more damage than trees wrapped with mesh netting.

How to help trees to recover from a cicada infestation

Most trees can recover from cicada damage on their own, but there are steps you can do to help revive your trees and shrubs.

Removing damaged branches may help a tree's overall health. It also allows the surviving branch stems to sprout and resume healthy growth. Taking care of the soil around the tree and fertilization will help lower stress and promote recovery.

CONTRIBUTING Meg Muckenhoupt and Cheryl Fenton, Reviewed; Sarah Bowman, Indianapolis Star

SOURCE Missouri Department of Conservation, University of Connecticut, University of Georgia Extension and USA TODAY research

This article originally appeared on USA TODAY: Cicada Brood XIII, Brood XIX damage to trees and shrubs: How to manage