Where were you in 2004? If you live now where you lived then, you may have an idea of what the potential is for periodical cicadas in your backyard. Depending on where you live, this could be a big deal, or, maybe, much ado about nothing. If they emerge in your landscape or home orchard, are you ready?
I remember 2004. I remember the news reports from Indianapolis television stations on the emergence of Brood X of the 17-year periodical cicada (I wasn’t getting the Fort Wayne stations at the time). In regions around Indianapolis and south, it was a big deal, and a sight to behold. Some locals I’ve talked to said they were everywhere. In my northeastern Indiana backyard…not so much.
This year’s 17-year brood, offspring of the 2004 adults, may appear in all counties, but heaviest emergence will be in south-central Indiana. Periodical cicadas appear in the last part of May through June.
Since emergence is possible in all Indiana counties, it is prudent to be prepared.
Let’s start with some good news: cicadas do not affect vegetables. Elizabeth Long, Purdue entomologist, also said that periodical cicadas won’t bite or sting people or pets.
“The bad news is females lay eggs in 200+ woody tree species and can cause severe damage to young trees,” she said. “Apples, cherries, peaches, plums, and grapevines are at high risk, because these hosts are preferred for egg laying by female cicadas.” She added that young trees with main branches and stems between 3/16” and 7/16” in diameter are susceptible to damage, and so these trees should be the main focus of protective efforts.
If you have young trees, or if you plant trees this spring, protect them with a 3/8” mesh (or smaller) insect netting while cicadas are present. Long recommended nothing larger than one-half inch. “Cover trees and tie the netting to the trunk below the lower branches,” she said.
If you don’t get trees covered and branch damage occurs, Long said to prune branches to remove damaged wood and infested branches after egg laying ends.
Larger trees can generally tolerate egg laying damage, but in orchard situations, some additional insecticide applications may need to be applied to protect trees.
Long offered these “take home messages:”
• 17-year cicada emergence will occur in all Indiana counties late May through June, but will be heaviest in south-central Indiana.
• Female cicadas damage twigs and branches 3/16” to 7/16” in diameter by cutting into them to lay eggs.
• If you have an orchard or backyard fruit trees: prepare to take action when you hear the first males begin to “sing.”
• Focus protective efforts (netting, insecticide applications) on young trees, because they are most vulnerable.
• Select and use insecticides judiciously to reduce flare-ups of secondary pests, like spider mites.
Purdue Extension has launched a website dedicated to the emergence of the 17-year cicada where you can find many helpful resources. Find the website at https://extension.entm.purdue.edu/cicadas/.
Find Long’s original article, which I have referenced excerpts from, in the March 26, 2021 issue of Purdue Facts for Fancy Fruits newsletter, at https://fff.hort.purdue.edu/issue/21-01/. Find my previous article on cicadas at https://extension.purdue.edu/Whitley/article/40159.