How Do Spotted Lanternflies Damage Trees? Key Facts to Know

The United States has battled an invasive insect for several years now. If you’re curious about how Spotted Lanternflies damage trees, read this blog to learn more. By staying informed, you can help prevent its spread to other states.

The Spotted Lanternfly is native to China and Southeast Asia. Experts consider this insect an invasive planthopper. It was first found in the United States in 2014 in Berks County, PA.

The SLF (Spotted Lanternfly) is not as threatening in Asia as it is here. In Asia, natural predators keep its population in check. Since there are no natural predators here in the U.S., we must control its spread.

Why Are Spotted Lanternflies a Danger to Trees?

Spotted Lanternflies are a serious threat because they feed on tree sap, weakening trees over time. As they continue feeding, trees become more vulnerable to disease and pests.

Additionally, they excrete honeydew, which encourages mold and fungi to grow. Over time, this mold further damages trees and nearby plants. Since they spread quickly, they can harm forests, orchards, and ecosystems across wide areas.

What is a Host Tree?

A host tree is a tree that provides food, shelter, or both to specific organisms, such as insects, fungi, or parasites. For example, certain insects, like the Spotted Lanternfly, rely on specific trees for survival. These insects feed on the sap or other parts of the tree, using it as a primary source of nutrition.

Host trees are crucial to the life cycle of the organisms that depend on them. Spotted Lanternflies prefer the Tree of Heaven (Ailanthus altissima), though they can also feed on many other types of trees.

Host tree vulnerability can shift: A healthy tree might resist becoming a host, but factors like drought, pollution, or injury can make it more vulnerable to becoming one.

Host trees often face secondary infections: Trees weakened by insect feeding or fungal growth are more likely to succumb to secondary infections or other environmental threats.

Chemical signals attract insects: Some host trees emit specific chemicals that attract pests or insects, such as sap or volatile organic compounds that draw in organisms.

What Are the Life Stages of the Spotted Lanternfly?

1. Egg Masses (Late Fall to Early Spring)

• Females lay egg masses on tree trunks, rocks, or other flat surfaces.
• Each mass contains 30-50 eggs, and a protective waxy coating covers it.
• Eggs overwinter and hatch in the spring, allowing them to survive cold temperatures.

1. Nymph Stage (Spring to Early Summer)

• After hatching, the Spotted Lanternfly enters the nymph stage.
• Nymphs go through four developmental stages, called instars, and cannot fly.
• They are black with white spots in the early instars and turn red in the final instar before becoming adults.

1. Adult Stage (Late Summer to Fall)

• Adults develop wings and can hop or glide to new areas, spreading easily.
• They primarily feed on tree sap from various plants, including grapes, fruit trees, and hardwoods.

1. Mating and Reproduction (Late Fall)

• After feeding, adults mate and lay egg masses, continuing the life cycle.
• Adults die off after laying eggs, but the egg masses remain, ready to hatch in the spring.
• This life cycle allows Spotted Lanternflies to multiply rapidly and spread over wide areas, making them difficult to control.

How Can Spotted Lanternflies Damage Trees?

Now that you know some basic facts about this invasive insect, you are ready to learn what they can do to trees.

How do Spotted Lanternflies damage trees? They suck sap from the tree’s leaves, branches, and trunk. As a result, it expels honeydew, which promotes sooty mold and fungi. Besides this, the released honeydew attracts other insects that also feed on the tree.

SLFs can also damage and weaken trees by reducing photosynthesis. Trees need photosynthesis because it is how they get food from sunlight. The leaves trap sunlight in the form of sugar. Then, they store the sugar in cells as glucose, which allows them to have healthy growth.

The honeydew from Spotted Lanternflies creates a sooty mold that covers the leaves. This mold blocks sunlight, stopping the leaves from performing photosynthesis. As a result, trees affected by Spotted Lanternflies often look sick and weak.

What Trees Are at Risk?

Since the Spotted Lanternfly likes to feed on fruit, ornamental, and woody trees, several trees in Connecticut are at risk. According to Connecticut’s Official State Website, 47% of the forest trees in Connecticut are susceptible to the SLF.

Some of the fruit trees that are in danger include apples, cherries, peaches, and grapes. There is a possibility that the SLF does not entirely kill the tree. But it could destroy the fruit’s value. As a result, the state’s agricultural industry could be really affected.

The list of trees at risk is quite large, but some examples include:

• Almonds
• Apricots
• Beech
• Elm
• Maple
• Nectarines
• Oak
• Pine
• Plums
• Sycamore
• Walnut
• White Ash
• Willow

We recommend that you contact your state’s Department of Agriculture whenever you notice SLF in your yard.

How Can You Treat Spotted Lanternflies?

If you’re dealing with Spotted Lanternflies, there are several DIY methods you can try. First, you can scrape off and destroy egg masses found on trees or outdoor surfaces by placing them in rubbing alcohol or hand sanitizer. Next, consider using sticky bands on tree trunks to trap nymphs and adults as they crawl up the tree. Additionally, applying neem oil or insecticidal soap can help reduce their numbers on smaller plants.

While these methods can help control the problem, infestations can grow quickly. For more comprehensive and lasting results, it’s best to contact a professional pest control service. Professionals have the tools and expertise to effectively treat larger areas and prevent future infestations, ensuring your trees and landscape remain healthy.

Infections and diseases are among the reasons for tree removal. If SLF has completely infected your tree, we recommend calling a professional to remove it.

For more expert advice on managing Spotted Lanternflies and protecting your trees, feel free to contact us today!