by Maria Maring
Land Conservation Coordinator
It destroys ecosystems and decimates crops, hitches a car ride when you’re not looking, and might be in your backyard right now. It’s the spotted lanternfly (Lycorma delicatula), a nonnative, invasive bug that has now reached Tennessee.
Its pursuit? Manifest destiny.
An invasive species – which could be a plant, insect, mammal, bird, or fish – expands out of its native range and dominates elsewhere. In some cases, invasives are able to take over ecosystems because they have an advantage over native life. Or, their natural predators don’t exist in these foreign landscapes to keep their population in check.
For example, honeysuckle is one of the most well-known invasive plants in Tennessee, where we have both Japanese honeysuckle (Lonicera japonica) and bush, or amur, honeysuckle (Lonicera maackii). Honeysuckle’s advantage? They are one of the first plants to leaf out in the spring, giving them an extra month or two ahead of native plants to grow and become well-established. As the dense honeysuckle canopy quickly forms in early spring, native plants are shaded out. The understory of entire forests can quickly become a monoculture of nonnative plants this way; a frightening thought.
‘If allowed to spread without management, the spotted lanternfly will wreak untold havoc on our native ecosystems, agricultural systems, and economy’
Invasive species are often transported by human factors, too, whether that be on purpose or by accident. The European starling (Sturnus vulgaris) is one such example; a bird that was intentionally introduced to New York City’s Central Park because some literature enthusiasts believed that every bird mentioned in Shakespeare’s works should be present in the U.S. Today, giant flocks of starlings patrol the skies like dark, angry clouds all the way from Alaska to Mexico.
The arrival of the spotted lanternfly, on the other hand, was accidental: A lanternfly egg mass probably hitched a ride on a boat from China to Pennsylvania in 2012. And as of the publishing of this article, the pest is in 16 states after it was first spotted in Davidson County, Tennessee in September 2023.
It’s caused quite the ruckus since. But why?
The spotted lanternfly is so concerning because it poses a huge threat to agriculture. If you like beer or wine, I’ve got bad news: The lanternfly loves hops and grapes. Also at risk are almonds, apples, apricots, nectarines, peaches, and plums. Lanternflies also feed on native trees like maples, oaks, poplars (including Tennessee’s state tree, the Tulip poplar) and more. So far, over 70 species of trees and crops have been identified as favorable lanternfly host plants; another frightening thought.
These deceivingly-pretty pests are efficient and detrimental feeders, too. They possess a piercing mouth that allows them to penetrate a tree’s bark and eat the sap underneath. Furthermore, the pest’s excretion – a sweet, sticky fluid called honeydew – attracts other pests and causes a fungus called sooty mold to grow. Wounds, honeydew, and sooty mold harm trees and crops, and they decrease a plant’s resiliency to other stressors like diseases and weather events. They also spoil crops, causing fruit to taste rotten.
In short: If allowed to spread without management, the spotted lanternfly will wreak untold havoc on our native ecosystems, agricultural systems, and economy. Which is exactly why limiting the spread of the spotted lanternfly is an all-hands-on-deck effort.
In kind, here’s everything you need to know about Lycorma delicatula.
What does the spotted lanternfly look like?
The appearance of the lanternfly depends on what lifecycle stage it’s in. This can make identification a little tricky, so let’s break their appearance down by those stages.
Egg mass
- An egg mass looks like a smear of dry mud.
- One mass can contain up to 60 eggs.
- Underneath the mud-like outer layer are parallel rows of eggs, each row being about one inch long.
- Many egg masses can occur in one small area.
- Eggs are laid in autumn, endure the winter, and hatch in spring.
Early nymph
- In its early nymph stage, the lanternfly is black with white spots.
- It has a cute, protruding nose, and it holds itself up by its powerful legs.
- The quarter-inch nymph can run and jump very quickly to find their favorite host plants to feed on.
- Witnessing nymphs – whether it be just a few or thousands – scurry up and down a tree can be a frightening sight.
Late nymph
- By the time it reaches its late nymph stage in summer, the lanternfly has grown to three-quarters of an inch long.
- It still has white spots, but by molting over and over again, its dominant color is now red.
- One could say that, by this point, it looks like the creepy cousin of the idyllic ladybug.
Adult
- Come late summer, the adult spotted lanternfly is admittedly beautiful. When resting, only the forewings are visible, which are a muted pink-brown color with large black spots on the upper half and finer spots on the tips. But when they prepare for flight, the lanternfly reveals its iconic, bright red hindwings.
- Its wingspan is a whopping two inches wide.
- Adult lanternflies are sexually dimorphic, meaning that the males and females look different from each other:
- Females are larger and have a red rear end.
- Males are smaller and have a dark rear end.
- Knowing the sex of the lanternfly is important information for scientists to track and study their westward expansion.
Where can I find a spotted lanternfly?
Female lanternflies are not picky about where they lay eggs. Egg masses can be found on vines, tree trunks, rocks, fence posts, lawn furniture, vehicles, outdoor equipment, and more – even folding camping chairs! Basically, egg masses could be anywhere, so it’s important to always keep a diligent eye out for them.
Early stage nymphs like to feed at the tops of trees, where the plant growth is young and easy to eat. At dusk, though, lanternflies of all ages tend to gather in large groups at the bases of tree trucks and plant stems.
Individual lanternflies are most often found on its many host plants, especially its preferred host, tree-of-heaven (Ailanthus altissima).
Trickily, nighttime is the best time to hunt for lanternflies. You can often find early nymphs, late nymphs, and adults all congregated together on the same plant.
And what does an infested plant look like? When a tree or crop has been a lanternfly meal, it may ooze or weep from its wounds, where the pests have penetrated the plant to eat. The plant may also have a fermented odor, which is the honeydew and sooty mold.
What should I do if I find a spotted lanternfly?
If you find an egg mass, take a photo, note the location, and report your finding to the Tennessee Department of Agriculture using their Report a Pest tool.
- To dispose of the egg mass, you’ll need a plastic baggie containing rubbing alcohol or hand sanitizer. Then:
- Crush the nest and scrape it into the baggie to sterilize it.
- Seal the bag and dispose of it in the trash.
- If these supplies aren’t available, still scrape the egg mass off the surface and crush it as best as you can.
If you find a lanternfly in its nymph or adult stage, kill it.
- Then, take a photo, note the location, and send in the information via Report a Pest.
- If it’s an adult, try to photograph the belly (as opposed to the back and wings), so that a scientist can identify its sex.
- This information is important because where females are found, there may be a colony.
What else can I do to prevent the spread of invasive species?
The spotted lanternfly cannot fly long distances. Instead, they are spread by human activity when egg masses or individuals hitch a ride on shipped goods or vehicles. So, before you dig your kayak out of the shed and tote it to the river, inspect its surfaces for muddy egg masses.
Regularly check your vehicle and other things exposed to the outdoors – like trailers, recreational equipment, and even clothing – for evidence of lanternflies, too, especially when traveling from a location with a known infestation. Of course, if you find any egg masses, dispose of them promptly and properly.
One of the best ways to curb the spread of Lycorma delicatula, however, is to eradicate its preferred host plant: Ailanthus. Ailanthus is yet another nonnative invasive species. Like invasive honeysuckles, it quickly takes over entire ecosystems, so we need to be vigilant with these plants, too.
Sadly, Ailanthus is prevalent in the entire eastern half of the US as well as in California today. Managing this species is in itself necessary to preserve the integrity of both our forests and our urban tree canopy, too, so eliminating it to curb the expansion of the lanternfly is a win-win.
To stay up to date on other invasive species, conservation updates, and more, be sure to sign up TennGreen’s e-newsletter!
Image Credits:
An illustration showing the lifecycle of the spotted lanternfly (Lycorma delicatula, photo credit: Molly Schafer)
A spotted lanternfly egg mass on a tree, with a hand for size reference. Photo credit: Lori Chamberlin.
A spotted lanternfly in its early nymph stage. Photo credit: GummyBone.
Many spotted lanternflies in their late nymph stage. Photo credit: arlutz73.
Adult lanternflies gathered on a tree. Photo credit: US Department of Agriculture.
A spotted lanternfly infestation. Photo credit: Pennsylvania Department of Agriculture.