Spotted Lanternfly's invasion of Michigan following the footsteps of its favorite invasive tree

(FOX 2) - Two invasive species - one that's beautiful-looking and another with a name that's beautiful-sounding - are presenting some tricky problems for wildlife managers in Michigan.

The spotted lanternfly and the tree of heaven represent the two ingredients posing a major concern to the state's agricultural economy as well as its resident's gardens.

The tree has already established itself in Michigan and the lanternfly isn't too far behind. It's already made a home around Metro Detroit and officials expect its spread to slow down.

The backstory:

The spotted lanternfly first arrived in the U.S. in 2014 when it was discovered in Pennsylvania. Despite the use of insecticides and efforts to remove the species' preferred host tree, it spread with ease and established itself within two years. 

It has since infested 19 states, including Michigan when it was found in Pontiac in 2022. It now populates Monroe, Macomb, Wayne, Lenawee, and Oakland counties - and will likely find suitable habitat throughout the rest of the state.

Spotted lanternfly are a type of planthopper, of which several other native variants call Michigan home. But the specific species is native to China, likely hitchhiking to the U.S. through shipments between the two countries. 

While it poses no threat to humans, spotted lanternfly have hurt Michigan's economy. It sucks the sap out of vines that grow grapes and hops, hurting the state's beer and wine industries.

Spotted lanternfly eating habits

When the lanternfly feed on trees, they use their mouthparts to pierce the inner layer of bark. Their goal is to access the phloem and reach the sap inside.

Because sap is mostly sugar and water, the species has to process a lot to get the nutrients it's after.

It excretes the rest into a substance called honeydew, which can draw swamps of wasps and ants before turning into mold - killing the leaves it comes into contact with.

Invasive Tree of Heaven

According to Deborah McCullough, spotted lanternfly's spread is only half the story of the invasive species' spread throughout the U.S. It is known to use over 70 different native hardwood trees as hosts.

"But what is driving spotted lanternfly is tree of heaven," the forest entomologist said in late July. 

Dig deeper:

Tree of heaven is also native to China and is the preferred host tree of spotted lanternfly. Wherever the pest has spread, it is likely the invasive host tree is nearby.

"It's an interesting tree and not in a good way," McCullough said.

Its first arrival in the U.S. was when it was imported to Pennsylvania by wealthy residents from England in the late 1700s. It has since spread across the country, growing anywhere it can find sun.

A single mature tree of heaven can produce 300,000 seeds a year, outcompeting native plant species with the help of toxic chemicals it releases to contaminate the soil. This prevents other seeds from germinating.

The fast-growing tree relies on an extensive root system to grow. It sprouts yellow seed pods when it spreads. It is sometimes mistaken for black walnut and sumac species that are native to Michigan.

McCullough said it sometimes smells like rotten peanut butter. 

The tree of heaven also poses a danger to humans. Its sap can cause nausea and heart issues when exposed to it.

One-sided symbiosis 

Despite its creeping invasion into the Midwest, spotted lanternfly ironically poses little threat to other trees. McCullough said there's little evidence the pest has killed native trees.

The only one it does kill is tree of heaven.

When the host tree is nearby, a lanternfly almost always chooses it as a home when it lays its eggs. Females often lay two masses that can have approximately 50 eggs each. 

"When you have tree heaven and you have other species of trees near those tree of heaven, then you're going to see feeding by the nymphs and by the adults of some other species," said McCullough.

What you can do:

Speaking during a webinar on the invasive species, McCullough advised the best way to prevent the spread of spotted lanternfly is to remove any egg masses found on trees, placing them in a bag and spraying alcohol on them.

An insecticide also works, with McCullough recommending pyrethroids. Another insecticide called Dinotefuran also works by spraying it on the tree that lanternfly are using. It's fast-acting but best used on trees that are done flowering for the season - often by the end of July.

Controlling tree of heaven is a different beast because of its extensive root system and resprouting ability. 

The best controlling method is by targeting the roots with herbicides, normally after July. It can be added to the leaves, bar, or cuts within the stems to effectively target the tree. 

Anyone targeting the trees for treatment should be wary of the health concerns from exposure to sap and the pollen it produces. 

EnvironmentMichiganWild Nature