Hanging broken twig tips caused by periodical cicada egg-laying, is the legacy of the Lower Mississippi Valley Brood of the periodical cicada. Nikki Bell, Marshall County Extension Agent, reported seeing dead tips last week. Female cicadas make longitudinal slits near the ends of small twigs and insert small batches of eggs in these wounds. Injured twigs often snap at the damage site, hanging as brown farewell “flags,” a final reminder of the vanishing brood.
Healthy, established trees generally will not be harmed even though twig die-back may be significant; however, small trees and shrubs may be deformed and could require corrective action at some point. The real impact on trees may come in 6 or 7 years as the root-feeding nymphal stages grow and remove progressively more sap from plant roots, reducing plant vigor and growth. There is no insecticide alternative; the best action is to provide water and fertilizer as needed and reduce stress on the plants when possible.
By Lee Townsend, Extension Entomologist