Tips for Preventing Egg-Laying by 13-Year Periodical Cicadas

Periodical cicadas, especially the 13-year species, are fascinating insects known for their synchronized emergence after spending over a decade underground. While their appearance is a natural marvel, they can sometimes pose challenges to gardeners, orchardists, and homeowners. One of the main concerns is their egg-laying behavior, which can damage young trees and shrubs. In this article, we will explore effective tips and strategies to prevent egg-laying by 13-year periodical cicadas and protect your plants during these cyclical invasions.

Understanding 13-Year Periodical Cicadas

Before diving into prevention tips, it helps to understand the biology and life cycle of 13-year periodical cicadas:

• Life Cycle: These cicadas spend 13 years underground as nymphs, feeding on root sap. They emerge en masse in spring or early summer.
• Emergence and Mating: After emerging, males sing to attract females. Once mated, females lay eggs in slits they cut into small branches and twigs.
• Egg-laying Damage: The females’ egg-laying causes “flagging” where twigs wilt and die due to the damage from egg insertion. This can stress young trees or reduce crop yields.

Because they emerge in massive numbers simultaneously, even a few years of heavy cicada activity can cause noticeable harm to susceptible plantings.

Why Prevent Egg-Laying?

While mature trees usually tolerate cicada egg-laying without severe long-term effects, young trees and delicate shrubs are vulnerable. The following issues may arise from unchecked egg-laying:

• Branch dieback: The slits made for eggs cause twig and branch tips to dry out and die.
• Reduced growth: Trees divert resources to healing damaged branches rather than growth or fruit production.
• Increased susceptibility: Damaged plants may become more vulnerable to diseases or insect pests.
• Economic loss: For orchards or nurseries, cicada egg-laying can reduce crop quality and value.

Therefore, preventing or minimizing egg-laying on valuable or young plants is essential during a cicada emergence event.

Tips for Preventing Egg-Laying by 13-Year Periodical Cicadas

1. Use Physical Barriers

One of the most effective methods to prevent females from reaching branches is to physically block access.

• Fine Mesh Netting: Cover small trees or shrubs with lightweight mesh netting that has holes smaller than the cicadas’ size (about 1/8 inch or less). This prevents females from landing on branches.
• Timing: Install netting just before cicadas begin emerging (usually late April to early May) and remove it after the emergence ends (typically 4-6 weeks).
• Secure Edges: Make sure netting is tightly secured around trunks or bases so cicadas cannot crawl underneath.

Using physical barriers is especially practical for young, valuable plants that you want to protect fully.

2. Prune Vulnerable Branches Before Emergence

Pruning can reduce the amount of suitable egg-laying sites on your trees.

• Remove Weak or Thin Twigs: Females prefer thin branches less than about half an inch in diameter for laying eggs.
• Perform Pruning Months in Advance: Prune in late winter or early spring before cicada emergence to avoid stressing plants during active growth.
• Dispose of Cuttings Properly: Remove pruned material far from plantings to avoid attracting cicadas.

Reducing vulnerable twigs makes your trees less attractive targets.

3. Plant Cicada-Resistant Species

Certain tree species are less favored by periodical cicadas for egg-laying.

• Species Less Affected Include:
• Oaks (some species)
• Maples
• Dogwoods
• Pines
• Avoid Highly Susceptible Species Near Orchards: Fruit trees like cherries, plums, apples, and peaches are preferred sites.

If planning new plantings in areas prone to cicada broods, consider planting resistant species to minimize damage.

4. Delay Planting Young Trees Until After Emergence

If possible, time your planting schedules around predictable cicada emergences.

• Since these cicadas emerge every 13 years in designated broods, you can plan to plant new saplings after they have completed their cycle.
• Newly planted saplings are especially vulnerable during their first few years due to tender twigs; avoiding exposure during peak emergence years protects them.

5. Water and Fertilize Plants Properly

Healthy plants can better withstand minor damage caused by cicada egg-laying.

• Maintain Adequate Moisture: Water regularly during dry periods leading up to and during emergence.
• Provide Balanced Fertilization: Use fertilizers appropriate for the species and soil conditions but avoid excessive nitrogen that promotes weak growth.

Robust tree health helps reduce long-term impacts from twig dieback.

6. Use Sticky Bands on Tree Trunks

Sticky bands applied around trunks may trap adult females as they climb up to lay eggs.

• Apply bands before emergence begins in spring.
• Use commercially available tree banding tape designed not to harm bark.

However, this method offers limited protection because many cicadas fly directly onto branches without climbing trunks first.

7. Avoid Using Insecticides Against Cicadas

Though it might be tempting to use pesticides against cicadas, these insects are generally resistant, and broad-spectrum insecticides can harm beneficial pollinators and wildlife.

• Most insecticides do not effectively prevent egg-laying because females remain active only for a short time.
• Instead of insecticides, focus on physical barriers and cultural controls outlined above.

Consult with local extension services for updated recommendations on pest management related to cicadas.

8. Monitor Emergence Timing Each Year

Understanding when a brood will emerge allows you to prepare ahead of time.

• Track local extension service reports about expected emergence dates.
• Observe first signs such as nymph exuviae (shed skins) on tree trunks or ground.

Early detection helps implement preventative measures promptly.

Summary

Preventing egg-laying by 13-year periodical cicadas requires a combination of cultural practices and physical interventions aimed at reducing female access to vulnerable branches. Key strategies include:

• Covering young trees with fine mesh netting during emergence periods
• Pruning thin twigs that females prefer for laying eggs
• Planting resistant species when possible
• Ensuring overall tree health through adequate watering and fertilization
• Planning planting schedules around predictable emergences

By taking proactive steps informed by the biology of these fascinating insects, gardeners and growers can minimize damage while still appreciating the unique phenomenon that periodical cicadas represent. With proper preparation every 13 years, your plants will be better protected against the temporary but intense stress caused by these ancient insects’ remarkable life cycle.