And (if so) What Can You Do About It?
As Brood X cicadas emerge in Somerset, PA, you might wonder, “Do cicadas damage trees?” Also, how do you keep cicadas off trees to begin with? Thankfully, at STS Arborists, we’re familiar with all kinds of tree pests and how to deal with them. And since trillions of them are about to emerge, it’s a good idea to be prepared.
While cicadas can deal damage to your trees and shrubs, their impact varies depending on the situation. Here are common instances where they can be a problem.
Cicadas Can Hurt Newly Planted Trees
Young trees are particularly vulnerable to cicadas. But you can use netting to protect your leafy buddies. We agree with the TCIA (Tree Care Industry Association) that a 1.0 cm (roughly 0.4 in) mesh netting works best. Amazon has some nets with even smaller mesh and those will keep out other insects too. But the most important thing is to avoid going over 1.0 cm. As TCIA notes, “Mesh size does matter. While 1.0 cm mesh performed well, when mesh size increased to 2.5 cm, cicada damage was as severe as that of untreated trees [emphasis added].”
Established Trees Are Also Prone to Cicada Damage
While Brood X cicadas (and cicadas in general) only emerge for six weeks, they can cause a lot of issues in a month and a half. During their noisy stay above ground, they mate and lay eggs inside branches of established trees. This leads to a condition called “flagging” that causes branches and twigs to die.
You’ll be able to spot flagging pretty easily if you know what to look for. Essentially, a cicada damaged tree that is experiencing flagging will have slits along the branches where the females laid their eggs. Here’s a few images to give you a better visual.
How Can I Avoid Tree Branch Flagging?
If you’re trying to avoid cicadas damaging your established trees, wrapping them should do the trick. In a recent CNET article about cicadas and tree damage, entomologist Frank Meek noted that, “You’ll need to wrap around the tree trunk and where the twigs meet the branch.”
According to that article (and many other people who have successfully prevented cicada tree damage) there are a number of products you can wrap a tree with. These include “cheese cloths, foil tape, barrier tape or sticky tape.” We would recommend cheese cloth as it won’t stick to the bark and can be easily removed when you no longer need it. Simply wrap as Meek recommends and secure it with tape.
Did Cicadas Already Damage Your Trees?
So, Is Cicada Tree Damage a Big Deal?
If you have young trees that were recently planted in the last few years, you should probably put a tree net on them. Simply put, cicadas and newly planted trees don’t mix well with each other. Since they are still getting established, they would benefit from the added protection.
When it comes to larger trees, it depends. The damage that cicadas cause is mostly superficial and will even “provide trees a service by pruning the weak branches of a tree. Cicadas lay eggs in the branch, weak branches wither and die (“flagging”), and the tree benefits from that by not having to waste energy on a weak or diseased branch. Cicadas also do the trees a service by dying and releasing a vast amount of nutrients back into the soil.”
However, the TCIA does recommend “pruning of damaged branches” as it “may enhance wound closure and reduce structural defects in branches as they mature.”
What's Worked for You?
Have you ever tried protecting your trees from cicadas? If so, what did you do and was it successful? Let us know in the comments!