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17 year Cicadas #738837

Asked March 12, 2021, 9:21 PM EST

We were going to do a complete redo on landscaping on our home that we just purchased last year. I just on news about the seventeen yr cicadas arriving. Are they coming here to our county of delaware...live in Westerville. If they are, when should we plant our landscaping so it won't be destroy by these Cicadas. thank you for help!

Delaware County Ohio

Expert Response

Hi there, excellent question.  Here is the brood map for the next several emergences in the US:  https://www.fs.fed.us/foresthealth/docs/CicadaBroodStaticMap.pdf   Westerville may be seeing quite a few cicadas this spring.  It may be best to wait until next year to plant young trees and shrubs, as they seem to suffer the most.  Here is a factsheet that will be additional help as it mentions their preferred hosts.  I live in Worthington but I'm excited as an entomologist. Best of luck to you. 

Jenny Andon

Jennifer Andon Replied March 24, 2021, 2:17 PM EDT

Hello,

While you are concerned about the emergence of the Brood X 17-year cicadas, they are not going to decimate your new landscaping. Please be aware, these cicadas are not the locusts that can decimate crops in our or anyone else’s country.

There are a few practical measures you can take to preserve anything you plant now.

The cicadas emerge in either May or June. They stay around for 4-6 weeks, making a lot of noise, mating, and laying eggs before the larvae burrow underground. The egg laying time is the most crucial. If you can get to the eggs before they hatch, you stand a good chance of not suffering major damage.

Cicadas don’t eat trees or branches. The females create slits in the branches where they lay their eggs. The slits may weaken the tree branches and, over a long time, and many invasions, cause the branches to whither and die. But this takes a long time and an overly large emergence of the cicadas.

Once the eggs hatch in the slits in the branches, the larvae burrow underground and attach themselves to grass and tree roots and feed there for 17 years. There are also 13-year cicadas as well as 2-3-year cicadas. Their egg laying is the same.

Cicadas prefer to lay their eggs in branches ¼ to 1/5 inch in diameter. This means that they prefer the following tress: oak, maple, fruit (especially cherry and pear), Hawthorne, redbud, and young trees (newly planted). Because they prefer young trees, I would wait until next year to plant any new trees in your yard. If you have already planted, or have one of the trees named above, you can wrap susceptible branches with mesh netting. Mature trees can sustain cicada damage, young trees cannot.

If you see a lot of cicadas in your area followed by splits in tree branches, prune the branches off the tree within 6-10 weeks of seeing the insects. The closer to 6 weeks the better. That means you must be vigilant about inspection. If you prune the branches off, the eggs are removed prior to hatching and will not burrow underground.

Cicadas rarely deposit their eggs on shrubs or flowers unless there is a very large invasion and they have no other places to deposit them. A naturalist once said of cicadas, “Oviposition is visually impressive, but dynamically irrelevant.” Because cicadas need trees to survive, it is not in their best interest to kill their hosts.

The United State Department of Agriculture has a map that shows where the broods will emerge by year. Most of the cicadas that emerge this year will be in Western Ohio. Please go to this website to view the map: https://www.fs.fed.us/foresthealth/docs/CicadaBroodStaticMap.pdf

I don’t usually recommend You Tube as a source, but this website is an excellent video on the life cycle of the cicadas. It also has good video of what a slit branch looks like. If you are a bit squeamish, fair warning, there are many pictures of the critters but there are also many practical tips. https://www.rochesterfirst.com/news/brood-x-is-coming-cicadas-return-by-the-billions-in-2021/

This website is from Earth & Sky Magazine and has an excellent map of affected areas. https://earthsky.org/earth/17-year-cicadas-broodx-2021

I hope this helps. Please email us again if you need further information. And good luck to you on your new landscaping!

Christine H. Replied March 25, 2021, 4:33 PM EDT

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