NOTE: You can learn more about periodical cicadas by accessing our updated 2025 OSU Extension fact sheet titled, “Periodical Cicadas in Ohio,” that was posted in March. Click this hotlink to see the fact sheet:
https://ohioline.osu.edu/factsheet/ENT-58
Simple [Cicada] Minds Sing, “Don't You (Forget About Me)”
Adults belonging to Brood XIV (14) of the 17-year periodical cicadas (Magicicada spp.) have bid farewell to southern Ohio, singing “(I’ve Had) The Time of My Life,” after their dirty dancing. Now we’re all listening to AWB’s “Pick Up the Pieces.”
Periodical cicada females first focus their oviposition attention on the woody stems of trees and shrubs, preferring stems measuring no more than approximately 1/2 inch in diameter. They use their sharp, spade-like ovipositors to insert their eggs deep into the xylem (white wood).
The oviposition damage produces two characteristic symptoms associated with periodical cicadas. The destruction of the vascular vessels disrupts the flow of water through the xylem, causing leaves to wilt and eventually turn brow,n producing the characteristic symptom called “flagging.”
The shearing of the xylem fibers reduces the structural integrity of the white wood, causing stems to break, detach, and drop to the ground. The detached stem may have green leaves or leaves that have turned brown.
Flagging and stem breakage are apparent now and will continue to develop throughout the rest of the growing season. However, both symptoms are inconsistent with the vast majority of the oviposition damage not producing flagging or stem breakage. Consequently, the cicada damage has little impact on the overall health of affected trees.
Our trees evolved with our cicadas. Research has shown that oviposition damage primarily affects aesthetics. On the other hand, extensive flagging on young trees can be serious because more of the branches are the preferred size for oviposition.
Although the females prefer woody stems, they will jam their eggs into almost any living stem once the preferred sites are exploited. For example, it was common to find oviposition slits on the petiole and rachis of the compound leaves of ash trees (Fraxinus spp.). Even the stems of herbaceous plants such as poison hemlock (Conium maculatum) were targeted.
I could find no data on egg survival and hatch success when unusual oviposition sites are used compared to more traditional sites. However, as I noted in a previous BYGL Alert, I believe the nonselective egg-laying behavior means that plant stems simply serve as safe sites for the eggs.
Although Brood XIV (14) of the 17-year periodical cicadas have left the building, not only will the flagging and stem breakage continue to develop for the rest of this growing season, but both symptoms will linger on for several more seasons. It’s easy to mistake old periodical cicada damage for other plant problems, such as cankering diseases.
Selected References
Clay, K., Shelton, A. L., & Winkle, C. (2009). Effects of oviposition by periodical cicadas on tree growth. Canadian Journal of Forest Research, 39(9), 1688–1697.
https://cdnsciencepub.com/doi/10.1139/X09-090
Flory, S. L., & Mattingly, W. B. (2008). Response of host plants to periodical cicada oviposition damage. Oecologia, 156, 649–656.
https://doi.org/10.1007/s00442-008-1016-z
Miller, F., & Crowley, W. (1998). Effects of periodical cicada ovipositional injury on woody plants. Arboriculture & Urban Forestry (AUF), 24(5), 248–253.
https://doi.org/10.48044/jauf.1998.030
