An invasive species is an organism that is not native to a defined location and can cause harm to the environment, economy, or humans. They did not evolve in their present ‘new’ environment and have few to no natural enemies. Invasive species can often out compete native organisms. Examples of invasive species can be found in all classes of organisms including plants, animals, insects, and microorganisms.
Two examples of invasive insects that are having a major impact in Ohio are Spotted Lanternfly
and Box Tree Moth.
We will look at how fast these populations can grow. But here is some background on each insect.
Spotted Lanternfly:
Spotted Lanternfly (Lycorma delicatula) is native to China, India, and Southeast Asia (Vietnam, Cambodia, Laos, Myanmar, Thailand). In its native range, there are natural predators and parasitoids that have evolved to keep this insect in relative balance with nature.
In 2006, Spotted Lanternfly (SLF) was discovered in Korea – outside its native range. In 2014, the first discovery of SLF in North America was confirmed in Berks County Pennsylvania near Philadelphia. The first SLF in Ohio was reported in 2020. Since then, SLF has been reported as either individual detections or reproducing populations across the state. How did it spread so fast? Spotted Lanternfly are not great fliers, and the adults die in the winter. But, the adults are great hitchhikers on trains, trucks, cars, and campers, and SLF will lay eggs on any hard/rough surface, making those eggs great hitchhikers too.
Here’s where the math comes in! One adult female SLF after she mates can typically lay 30 to 50 eggs in a single egg mass, though some masses can contain up to 60.
Females often lay two or more of these masses between September and December, depositing them on trees, rocks, and many other rough outdoor surfaces according to Penn State University researchers.
So do the math on Spotted Lanternfly.
One adult female can lay clusters of about 50 eggs, 2 or 3 times in the fall.
If she just lays two egg masses that will be 100 eggs. If we assume a 20% survival rate thanks to our effort to squish them, some losses due to predation and general variability in fertility and other factors, that makes 20 new adults next spring. Let’s say half are females who mate and lay 2 egg clusters of 50 eggs. That’s 10 x 100 making 1,000 new eggs. Let’s do this for 4 years using a 20% survival rate will give us 200 new adults in spring of year two.
After 4 years, we could have over 100,000 eggs from just one female. If more than one mated female is introduced to an area, it adds up.
The first reports of SLF in Ohio, at Mingo Junction, Southeastern Ohio and in downtown Cleveland at a cemetery were both close to railroad tracks. Remember, Spotted Lanternfly are good hitchhikers.
With each year, the SLF population increased and spread to new areas. Fast forward to 2026, on February 17, the Ohio Department of Agriculture placed the entire state of Ohio is under a statewide quarantine. Even though there are still locations where SLF is not yet present, the probability is soon it will be found throughout the state of Ohio. With few natural predators and a diet of over 70 host plants, populations are likely to 'explode'.
Our second invasive species is Box Tree Moth:
The box tree moth (BTM) (Cydalima perspectalis) is native to temperate and subtropical regions of East Asia, including China, Japan, Korea, and India. It was introduced to Europe in 2006–2007 where it has become an invasive species. BTM was likely first introduced through the international trade of infested nursery stock. The infestation has spread rapidly due to the presence of native European boxwoods in natural areas and forests throughout the continent, providing locations for populations to reproduce unchecked. In North American, the first discovery of BTM was confirmed in Ontario, Canada, in 2018, and was likely introduced via imported plant material. It was subsequently found in New York 2021, in Michigan 2022, and in southwestern Ohio 2023. As of April 2026, BTM populations have been reported in nine states. Unlike Spotted Lanternfly, Box Tree Moth are strong flyers (natural spread is 3-6 miles per year); however, long-distance movement is primarily driven by the movement of infested boxwood plants according to Cornell University.
BTM is a member of the insect order Lepidoptera, and it has a four stage life cycle egg, larva, pupa and adult (complete metamorphosis). BTM is a bit special in that it overwinters in the larval stage in a hibernaculum, a silk and leaf “sleeping bag” that protects the caterpillars through the winter while they hibernate. The BTM caterpillars will awaken in the spring, feed, pupate, emerge as adults. The adults will mate and the females will begin laying eggs. This lifecycle is repeated throughout the spring and summer, BTM is reported to produce 2 to 3 generations in Ohio, but more generations may be possible in warmer climates.
So do the math on Box Tree Moth.
From a numbers standpoint, an adult female box tree moth lays roughly 150 to over 800 eggs in her lifetime (Cornell University). The eggs are pale yellow, gelatinous, and deposited in clusters of 5 to 20 (sometimes up to 50) on the undersides of boxwood leaves. These eggs typically hatch into larvae within 4 to 7 days.
Females have been reported to be capable of producing up to 42 individual egg masses in their short, 2-week adult life.
But let us error on the side of caution.
Let’s take one female adult. She lays a cluster of 10 eggs and in her entire life lays 20 sets of eggs. That’s 200 possible new larvae. If only 20% survive to adulthood, that’s 40 adults. Let’s assume a 50% male/female population. So that would leave 20 new adult females to lay eggs again that season, because BTM has several generations a year. Those 20 females lay another 200 possible eggs. That’s 4,000 eggs. Assume 20% survival rate, that’s 800 adults. 50% of that gives us 400 possible females. If we get a 3rd generation that year, those 400 females lay another 200 eggs each, at 20% survival, that’s 16,000 possible caterpillars overwintering ready to continue the process just after 1 year.
As you see, even expecting some mortality from environment and some predators, populations can explode.
So, what can be done and what is being done?
USDA – APHIS and Universities are researching the possible use biological controls for these invasive insects including predatory wasps or insect specific fungus. But because these biological controls could negatively affect native ecosystems through impacting non-target organisms, great care needs to be taken to methodically investigate what potential effect these organisms would have on native insect, plant, and animal populations.
Spotted Lanternfly Management:
While that research continues, Ohio Department of Agriculture published a great homeowner resource to control Spotted Lanternfly.
It can be found here:
https://agri.ohio.gov/divisions/plant-health/invasive-pests/slf-bmp
Some highlights include:
Managing egg masses
Egg masses may be destroyed prior to nymphs emerging, resulting in a reduction in the number of nymphs the following season.
Egg masses may be squashed—popping the individual eggs within the masses or by scraping egg masses with a knife or edge of a credit card into either soapy water (dish soap works) or rubbing alcohol which will kill the eggs.
Egg masses may be treated with horticultural oils during the winter months or before bud break in the spring.
Managing nymphs and adult SLF
Spotted Lanternflies can be managed using several different strategies depending on population density.
When populations are low, acceptable control may be achieved by swatting or stomping nymphs and adults when you see them.
Removing favored SLF hosts such as Tree of Heaven which is invasive and native Wild Grapevine, may result in a reduction in SLF populations on your property.
Horticultural oils and insecticidal soaps can provide control of nymphs and adults. However, they do not provide residual activity. These products would likely need to be reapplied throughout the season.
Contact insecticides with active ingredients as such bifenthrin, carbaryl or malathion may be used as spot treatments against SLF nymphs and adults. Repeated treatments may be necessary.
Systemic insecticide treatments with dinotefuran or imidacloprid can be used as trunk sprays, trunk injections, or soil drenches depending on the label, and do provide more prolonged protection.
Special Management Notes
Some of the products above may need to be applied by certified commercial pesticide applicators or may require specialized equipment to apply.
Protect Pollinators! Do not apply systemic insecticides when trees or shrubs are in flower, or if nearby flowering plants may take up the pesticide (as in soil drenches).
The site where you plan to use the insecticide must be listed on the product label. Remember to always use products in a manner consistent with the label. Even oils and soaps! The Label is the Law!
Box Tree Moth:
Ohio State University Extension has created a series of 3 fact sheets on BTM, the third listing management options listed below:
https://ohioline.osu.edu/factsheet/ent-0101
What Should You Do?
1. Do not make preventative insecticide applications to boxwoods unless an infestation has been confirmed.
Insecticide applications should only be made to boxwoods with an identified BTM infestation, or to those boxwoods in close proximity to a confirmed BTM caterpillar infestation. Making unwarranted insecticide applications is a waste of money and product and can also have unintended consequences including producing secondary pest outbreaks.
Research has shown that applications of synthetic pyrethroids can kill predaceous mites that help keep plant-feeding mites in check. This can then lead to plant-feeding mite outbreaks (Penman & Chapman, 1988; Gerson & Cohen, 1989). Systemic applications of the neonicotinoid insecticide, imidacloprid, which is a common insecticide targeting boxwood leafminer [Monarthropalpus flavus (Schank)] and boxwood psyllid (Psylla buxi L.), stimulates increased egg production (fecundity) of the boxwood spider mite, Eurytetranychus buxi Garman (Szczepaniec & Raupp, 2013). This mite has been on the rise over the past several years.
2. Monitor boxwoods
BTM infestations may pop up anywhere. Monitor for small green caterpillar with black stripes and black spots on boxwood.
3. If you see it, report it!
It is essential to identify the geographical distribution of BTM in Ohio. This knowledge will guide the development of BTM management plans. The Ohio Department of Agriculture (ODA) has developed an online reporting tool that allows reporting of BTM in three easy steps. Send a clear, in-focus picture(s) of BTM caterpillars into the plant pest reporter (link). You may also collect the caterpillars and preserve them in a freezer until they can be photographed. BTM caterpillars do not bite or sting, so they are safe to handle.
4. Management
Currently, tools that support a robust BTM integrated pest management (IPM) program must be fully developed (Coyle et al., 2022). For example, field observations and preliminary host preference trials have demonstrated that some boxwoods are less susceptible to BTM damage (Sisk et al., 2022).
BTM caterpillars may draw the attention of various predators. Yellowjackets (family Vespidae) have been observed grinding-up BTM caterpillars to feed to their young (Figure 5 in the factsheet). Assassin bugs (family Reduviidae) such as the wheel bug (Arilus cristatus L.) shown in Figure 6 have been found crawling within boxwoods heavily infested with BTM (Boggs et al., 2024).
So, there are some things you can do as a homeowner.
Just be aware that population can EXPLODE
in a short time.
