Spotted and damaging: New invasive insect spotted in Iowa

An adult Mottled Lantern perches on tree bark. (Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org)

CEDAR RAPIDS – The invasive spotted lantern – which sports an expansive diet of plants – made its first appearance in Iowa after spreading from the East Coast.

Two immature insects were identified earlier this month in Dallas County near Des Moines, the Iowa Department of Agriculture and Land Stewardship reported Tuesday. An alert resident reported seeing the red and black polka-dot lanterns — and, after federal identification, state entomologist Robin Pruisner said, “Damn, they were right.”

The spotted lanternfly was first detected in the United States in 2014 from stones imported by a Pennsylvania landscaping company, said Julie Urban, an evolutionary biologist at Pennsylvania State University who studies the ‘bug.

The sightings have since been confirmed in at least 16 states, according to New York State Integrated Pest Management. Iowa will mark the 17th state reporting the spotted lanternfly. Eleven of those states are experiencing infestations, with Indiana and Ohio being the hardest-hit spots in Iowa.

Although the area surrounding the Iowa detection did not show signs of infestation, the state’s agriculture department is urging residents to be on the lookout for the spotted lanternfly. Its varied and voracious appetite, as well as its hitchhiking prowess, could threaten the country’s grape, orchard, nursery and logging industries if it continues to spread.

What is a Spotted Lantern?

The spotted lantern is native to China, India and Vietnam. His favorite menu includes a wide variety of fruit, ornamental and woody trees and plants, such as grapes, hops, oak, apple maple and the invasive celestial tree.

Insects have a straw-like beak that sucks sap from plants. After being satiated, they excrete honeydew — a sugary substance where sooty mold can grow, Pruisner said.

“It kind of destroys people’s outdoor experience and can be hard on their landscape plants,” she said of the mold.

Mottled lanterns produce only one generation of insects per year, their eggs hatch between April and June. The resulting infants hop from place to place to sample their selection of host plants.

“They’re like little kids: they put anything in their mouth,” Urban said. “So that makes them hard to detect because they sort of diffuse through the environment.”

Older nymphs of the spotted lanternfly may sport a brilliant red color before emerging as adults. (Emelie Swackhamer, Penn State University, Bugwood.org)

Mottled lanterns moult several times before emerging around July as adult insects with wings. Although only about an inch long, they feed voraciously before mating and laying eggs beginning in August. Frosts kill the adults during the winter and the life cycle begins again once the eggs hatch.

Because they are so mobile and feed on a multitude of plants, Mottled Lanterns can infiltrate different industries, habitats, and neighborhoods. They can even lay their hitchhiker eggs on vehicles and trains, Urban said.

“The sacred thing about them is with this movement,” she said. “Because they are in constant motion, we have no idea how far they can travel.”

Difficult to calculate damage

Although spotted lanterns have a wide diet of plants, they don’t kill all of their meals, Urban said. The insect will be a stressor that many infected plants will survive. Additionally, spotted lanterns do not normally infect plants deep in forested areas, instead concentrating on trees and shrubs in disturbed areas.

“It’s not as bad as we thought when we sounded the alarm in 2017-18,” she said.

Still, the spotted lanternfly can render grapes unsaleable and kill their vines — which could devastate American vineyards if it continues to spread. And while it can’t wipe out other plants, it still leaves an economic hole in infected nurseries who must quarantine and manage their produce to prevent further spread.

For example, researchers at Pennsylvania State University projected high economic impacts on Pennsylvania – the initial epicenter of US outbreaks – in 2019, when only 14 counties were under quarantine. Economic losses of $50.1 million a year were expected for the state’s quarantine zones alone. With further spread throughout the state, researchers estimated losses at $324.9 million per year. At least 45 Pennsylvania counties are now in quarantine.

The possibility of a similar economic and environmental impact in Iowa is concerning. Although the state is well known for its corn and soybean crops, Iowa also contains orchards, small fruit growers and sensitive gardens, Pruisner said.

“It would be these specialized cultures that would feel the pinch of this insect,” she said.

How to Spot a Mottled Lantern

At this time of year, Mottled Lanterns should be in their pupal stages, where they sport a black and white – and sometimes red – color combination. When in large numbers, they are easy to see migrating along trunks at dusk or at night, depending on the agricultural department. During the day, they usually cluster at the base of the plant.

Although the spotted lanternfly can damage plants, it is not harmful to humans. If you think you have found a spotted lanternfly, you can call the Iowa Bureau of Entomology and Plant Science at (515) 725-1470 or email [email protected] You can also contact the Iowa State University Extension Office in your local county.

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