Are Cicadas Harmful to Plants and Trees?
If you're a gardener or tree lover, the sound of cicadas might make you wonder: Are these noisy insects harmful to my plants and trees? With their distinctive buzzing, cicadas are a hallmark of summer, but their impact on vegetation can raise concerns. Let's explore the relationship between cicadas and the greenery we cherish, shedding light on whether these insects are truly a threat.
Understanding Cicadas: A Quick Overview
Cicadas are fascinating insects known for their loud calls, which males use to attract females. They belong to the order Hemiptera and are divided into annual and periodical cicadas. Annual cicadas appear every year, while periodical cicadas emerge in massive numbers every 13 or 17 years, depending on the species. The Missouri Department of Conservation has an article for further reading.
The Life Cycle of Cicadas
To understand their impact on plants and trees, it's essential to know their life cycle:
Egg Stage: Female cicadas lay eggs in the twigs and branches of trees and shrubs.
Nymph Stage: After hatching, nymphs drop to the ground and burrow into the soil, where they feed on plant roots for several years.
Adult Stage: Mature cicadas emerge from the ground, shed their skins, and climb trees to mate, restarting the cycle.
Do Cicadas Harm Plants and Trees?
Egg Laying and Twig Damage
One of the primary concerns about cicadas is the damage caused by egg-laying. Female cicadas use a saw-like ovipositor to cut slits in small branches and twigs to deposit their eggs. This process can cause the following:
Flagging: The slits can lead to a condition known as "flagging," where affected branches die and turn brown. While this might look alarming, it typically doesn't cause long-term harm to healthy, mature trees.
Stunted Growth in Young Trees: Young or newly planted trees with thin branches can suffer more significant damage, potentially stunting their growth or even killing them if the infestation is severe.
Root Feeding by Nymphs
During their underground nymph stage, cicadas feed on tree and plant roots. This feeding generally doesn't cause noticeable damage, as most established trees can handle the minor stress from cicada nymphs. However, plants that are already stressed or young saplings might experience some growth issues. The Missouri Botanical Garden has an interesting article on this topic as well.
Managing Cicada Infestations
While cicadas can cause some damage, there are ways to protect your plants and trees:
Netting: Cover young or vulnerable trees with fine netting to prevent cicadas from laying eggs in their branches.
Pruning: After cicada emergence, prune dead or damaged branches to maintain the health of your trees.
Delay Planting: If you know a periodical cicada emergence is coming, consider delaying planting new trees and shrubs until after the cicadas have gone.
The Bigger Picture:
Cicadas and the Ecosystem Despite their occasional nuisance, cicadas play a crucial role in the ecosystem:
Soil Aeration: When cicadas emerge from the ground, their tunnels help aerate the soil, promoting healthy root growth.
Nutrient Cycling: The decaying bodies of cicadas provide a nutrient boost to the soil, benefiting plants and trees.
Food Source: Cicadas serve as a food source for various predators, including birds, mammals, and other insects.
Conclusion: Cicadas—A Minor Nuisance or a Major Threat?
In most cases, cicadas are not a significant threat to plants and trees. While their egg-laying habits and root feeding can cause some damage, healthy, mature trees generally recover well. Young plants and newly planted trees might need extra protection, but overall, cicadas are an essential part of the natural world, contributing to a healthy ecosystem.
So, the next time you hear the loud buzz of cicadas, you can appreciate their role in nature without worrying too much about your garden. Remember, with a little care and attention, your plants and trees can thrive, even during a cicada emergence. If you’d like to understand more about cicadas we have a blog post you may also enjoy.
By understanding the impact of cicadas and taking simple preventative measures, you can ensure your green space remains lush and vibrant, enjoying the summer sounds without the stress. The University of Missouri Extension has a few more tips on keeping trees healthy during cicada season.
