If you have serious concerns about your trees/plants, talk to an arborist or plant expert.
How can I prevent cicadas from damaging my plants? Assuming they actually will, there are several solutions I’ve heard people recommend. I did not test these methods.
- You can wrap netting, or insect exclusion screens, around small trees or individual tree limbs to keep the cicadas off them. You can get this netting from stores (in person or Online) that sell landscaping supplies.
- You can use insect barrier tape or a sticky solution like “Tanglefoot Pest Barrier”. Not my favorite idea, because it will probably pull their tarsal claws off.
- You can manually pick them off with your hand. Put your kids to work. A friend who lived in Italy told me she had to pick Cicada orni off vines at her family vineyard.
- You can spray them off with a hose. Just don’t spray the leaves of your trees in the process. Don’t use a power washer.
- See Green Methods for more ideas.
Here is an example of netting being used to contain cicadas, except in this case the cicadas are being kept next to the tree branch and not away from it:
As you might imagine, if the netting can keep them inside, it will also keep them outside.
Damage from cicadas occurs when the female cicada creates in the branch of a tree with her ovipositor (see video).
The ovipositor is sharp and able to carve into the bark and cambium of the branch. Damage from cicadas becomes visible in the form of “flagging” as branches die. This behavior is vital to cicada reproduction, and native species of trees have evolved to survive it. Weaker, petite, ornamental, and non-native fruit trees won’t fare as well. It seems counter-intuitive that cicadas would damage the very trees that they feed off of their entire lives (via root systems), but that is how they have co-evolved — with the cicada feeding on tree fluids & fertilizing trees when they die in return. Flagging can be positive for trees as well, as it prunes weaker branches. But again, weak, tiny, ornamental, fruit trees and non-native species aren’t adapted to this relationship with the cicadas.
We recommend that you don’t bother with pesticides for a number of reasons:
- New cicadas will continually fly onto your trees from neighbor’s yards, making pesticides futile.
- Your pets could become poisoned from ingesting too many treated cicadas.
- Collateral damage — you end up killing other insects like honey bees and butterflies. There is a lot of concern about the extinction of insects in general, as well as cicadas.