May and June will see the emergence of Periodical Cicadas Brood X (10).
In the Cincinnati area we will see unimaginable numbers of these insects emerge from the ground in early/mid May. Cicada activity will occur during a 4-6 week period.
While the insects don’t eat plants they can cause damage on trees and shrubs. After mating the female lays eggs on branches that are around 1/4″-1/2” in diameter. She does this by slicing through the bark and depositing the eggs in the branch. This slicing can cause damage to the branch. Often the branch will break where the eggs were laid. This is called ‘flagging’.
This damage is not a problem for large trees and they will recover with no adverse effects to their health. Smaller trees could see more substantial damage due to the fact that most branches on young trees are within the diameter range that cicadas prefer to lay their eggs.
While actual death of the tree is unlikely, significant damage is possible. Insecticides are not effective due to sheer numbers. Protection of young trees is most effective by physically barring the insects from laying eggs on branches.
White Oak Gardens offers a flexible, porous netting with ¼” grid spaces through which cicadas cannot pass.
This netting is 14’ x 14’ and will cover a tree that is around 6’-8’ tall and 4’-5’ wide. Two zip ties are included to secure the netting to the trunk. This netting should be put on trees susceptible trees around the last week of April (before the emergence in early May) and should be left on through June.
There are many factors that determine the risk of cicada damage to trees. Ultimately only you can decide if the time and cost of covering your young trees outweighs that risk.
Protect if possible…prune when necessary.
Brood X FAQs
When will cicadas emerge?
Cicadas will emerge when the ground temperature reaches 64 degrees which will likely occur in mid-May. Their life cycle lasts 4-6 weeks which means they will be around until the end of June.
Will cicadas eat my trees and shrubs?
A cicada is not like a grasshopper or locust, in that they don’t eat leaves or plants. Once it emerges from the ground, a cicada’s main job is to mate, lay eggs and die
If they don’t eat, how do they damage the trees and shrubs?
A female cicada will slice into a branch or limb (preferring those that are ¼ to ½ inch in diameter) where she will lay her eggs. The tip of those branches will die off and this is called flagging. Flagging is not an issue for larger trees, but for smaller deciduous trees the flagging can weaken the tree.
What trees are most susceptible to damage?
Small deciduous trees with branches ¼ to ½ inch in diameter are most susceptible. Evergreens, flowers, vegetables and shrubs are typically not heavily damaged by cicadas.
How can I prevent damage to my trees and shrubs?
Pesticides and other chemicals are not effective in controlling cicadas. The best way to protect a small tree or plant is to drape it with netting that is tied at the base of the tree. This netting prevents cicadas from climbing up the trunk of the tree or flying into the tree to lay eggs. The netting allows sunlight and water to pass through.