The hype is everywhere: We are being invaded by 17 year cicadas which emerge from the ground by the thousands every 17 years.The cicada nymphs hang out in trees, shrubs, and other plants, and then molt into adulthood. Adult males congregate in loud choruses, and fly together in search of females.
Should you be concerned about damage to your trees? Yes and no. The cicadas will feed on your tree’s leaves (see photo above by Steve Young) and egg laying by mated females does damage tree bark. The female cicada excavates a channel in small twigs or branches and deposits her eggs in the slit, effectively splitting the branch open. The ends of affected branches will brown and wilt. For most trees, there is no need to be concerned. The tree will look damaged for the rest of the growing season, but will bounce back next year. What to do?
Relax. Don’t spray insecticide. Marvel at the wonder of the spectacle of millions of cicadas visiting us. Your trees will survive as most trees have, for hundreds of prior visits by cicadas over the years.
I have read articles suggesting young trees be protected with netting like mosquito netting. You are to drape the netting over the entire tree canopy, and secure it to the trunk so no cicadas can crawl under the opening. Your netting will need to be in place before the cicadas emerge; remove it once all the cicadas are gone. Where do you find this netting? Good question. I’ve not yet found a website that sells netting for trees. (Bird nets will be ineffective) The products I saw require some fabrication to cover a tree. If you haven’t found netting by the time you read this article, you likely are too late anyway.
If you are planning to plant a new tree this year, wait until the fall, a better time to plant a tree.