Ohio is one of the states with a high number of invasive plants and animals. Its opening to The Great Lakes means the state enjoys a complex ecosystem.
Many invasive species in the state are growing in numbers constantly. Both animals and plants here might be displacing local populations and species within their spreading period.
Some of the most invasive species in the state also cause economic loss. For example, invasive aquatic species can clog waterways. Other dry land invasive plants can create monocultures by spreading and killing local plant species.
Invasive fish in the state are known to displace and even kill local fish populations. Trout is one of the species negatively impacted by invasive species in Ohio.
Here are some of the most impacting species of animals and plants in Ohio.
Table of Contents
Invasive Animals in Ohio
1. Wild Boar
Wild Boars (Sus scrofa) are believed to originate in Asia. They represent a common invasive species in the state of Ohio where they inhabit different habitats.
Also known as the ancestors of pigs, wild boars or hogs can live in almost any type of habitat including mountainous regions in elevations of up to a few thousand feet.
This is a species known for its grunts. Females grunt more than males and they also lead the social life of the group they live in.
Wild boars are highly adaptive in habitat and food preferences. They like to eat fruits, roots, insects, larvae, eggs, frogs, and even snakes.
As an invasive species, wild boars also help invasive plants spread as they eat through the soil disturbing the natural habitat.
2. Round Goby
Round Goby fish (Neogobius melanostomus) have an invasive status in Ohio and North America. This is an elongated tan fish that turns black as it matures.
It has been introduced by accident with shipping containers or cargo ships carrying water from other regions of the world just a few decades ago.
The area of The Great Lakes is believed to be the first sight of the species in North America.
It competes with native fish for food such as snails and it also eats fish eggs of various native species.
The Round Goby is a species difficult to eliminate from a habitat as it has high resilience in waters that aren’t perfect for fish.
The aggressive nature of these fish is also seen in how they defend their lain eggs. Male Round Goby fish defend their eggs from native species.
Ruffe fish (Gymnocephalus cernuus) are some of the introduced species in the area of The Great Lakes first to be discovered. This is a species that impacts local populations and scientists are trying to eliminate it from Lake Superior.
The fish matures in 2-3 years and it has very fast reproduction rates compared to local fish.
It eats various types of flies, a diet it has carried with itself from other regions of the world where the species is native.
The introduction of predatory species to control their numbers hasn’t been fully successful.
One of the elements which make the species highly dangerous for the local ecosystem is its long lifespan. Ruffe fish live anywhere between 7 and 11 years.
4. White Perch
The White Perch (Morone americana) is one of the species often confused with white bass. Found in the area of The Great Lakes, this type of fish is mostly in direct competition for resources with white bass.
This fish shows better adaptability to local food sources.
It can eat almost anything and it can adapt to different conditions which makes it superior to its native fish it outnumbers in some areas.
The species has stable and growing populations without being subject to conservation efforts both in and outside of the state.
5. Grass Carp
Grass Carp (Ctenopharyngodon idella) is an important species to Ohio and the world as it has been the first species to reach the most widespread farming status around the world.
This species is illegal to release in state waters as an invasive species. It has been introduced all around the world as it eats underwater vegetation but it also competes for resources with local species.
Unlike other invasive fish in Ohio, Grass Carp has very specific conditions and requirements to live which means it isn’t found all around the state.
Grass Carp is one of the species used in private ponds to control weeds but it cannot be released into streams and rivers.
Full control of the species is seen in many parts of the world as this fish has difficulties reproducing by natural means.
6. Silver Carp
Feeding on phytoplankton, Silver Carp fish (Hypophthalmichthys molitrix) are among the few invasive species without a stomach. This means this fish feeds constantly in its invaded Ohio range.
Silver carp is a fish known to move upstream for laying eggs and then moving down backstream.
Its numbers are increasing in North America but diminishing in its native China.
This is a species that fights for resources with local fish.
Growing to a maximum size of 39 inches, this species has an introduced status in the state.
It was first brought to control water algae but has now turned into a more serious problem for local bigmouth buffalo species.
7. Bighead Carp
Bighead Carp (Hypophthalmichthys nobilis) are a closely related species to Silver carp. Both of these species are filter feeders which means they can only ingest small types of algae with the Bighead Carp eating the larger particles.
This fish has an invasive status but it acts a bit differently from the Silver Carp. Bighead Carp cannot jump out of the water like Silver Carp.
Fish of this genus are known for their agricultural use as they are one of the most commonly farmed fish species in the world.
Its role in local ecosystems is highly damaging.
The damages the species make in Ohio and other regions are so extensive that other nearby states have banned all Bighead Carp imports.
The species might still be retailed but it cannot be bred.
8. Black Carp
Active action is being taken against invasive Black Carp species (Mylopharyngodon piceus) in Ohio. This is a species with a risk of high reproduction rates in The Great Lakes.
Generically known as an Asian carp, this is a species with a real threat in all US states. It feeds on endangered mollusks in the United States.
Releasing Black Carp in public waters is illegal in the state.
Black Carp is one of the most expensive species of fish in its native China. This fish has exclusive preferences when it comes to food which further drives its prices up.
Black Carp has also been used as a cure for various conditions in Asian traditional medicine.
Western territories of North America are now actively moving to stop the spread of Black Carp similar to the efforts of Northern states such as Ohio.
9. Sea lamprey
The presence of Sea lamprey in The Great Lakes is attributed to different causes with no one answer for its high numbers here.
This is one of the species (Petromyzon marinus) that theories say has made its way through the Erie Canal.
You can identify Sea lamprey by its jawless large mouth and its eel-like body.
This fish has no natural predators in the area of the Great Lakes and it becomes itself a predator to many types of fish.
Its highest ecosystem impact is on trout.
This species has a unique feeding pattern. It attaches itself to fish such as trout sucking its blood. Fish cannot escape its bite.
While an expensive food in some restaurants around the world, Sea Lamprey is a serious problem for trout and lake whitefish.
10. Zebra Mussel
Zebra Mussel (Dreissena polymorpha) is a type of invasive freshwater mussel in the area of The Great Lakes.
This species is one of the most problematic invasive mussels that reduce the food resources of local mussels.
Zebra Mussels are known to clog waterways as they attach themselves to different underwater objects.
The underside of boats is one of the areas these mussels are found. They can also attach themselves to anchors and different other underwater structures.
Zebra Mussels have been accidentally introduced to the area of The Great Lakes. It’s believed they made their way with ships traveling in from the Atlantic.
11. Codling Moth
Codling Moth caterpillars (Cydia pomonella) are an atypical species with a damaging role in the ecosystem.
They don’t feed on leaves like other caterpillars in Ohio but they feed on fruit.
Apples are the most impacted fruits by the presence of this species. Caterpillars eat the outer side of the fruit slowly boring into the apple and stopping its growth.
These caterpillars have a yellow-brown color in their first instars slowly turning darker brown.
Adult moths of the species have dark brown upper wings and light brown to cream underwings and a tan body.
Almost all of the damage to Ohio crops are caused by the Codling Moth Caterpillar as the adult moth doesn’t feed it only rarely feeds.
12. Gypsy Moth
It’s believed invasive Gypsy Moths (Lymantria dispar) are among the most common species to be accidentally released in Massachusetts making their way into Ohio and other states later on.
This is a species that impacts many types of deciduous trees in Ohio.
The state’s oak trees are among the species most notably known to suffer even from complete defoliation in case of outbreaks.
Identification of its caterpillars is based on their dark coloring with black and red nuances contrasted by long white or gray spike-like hairs.
These caterpillars are diurnally moving onto leaves in plain sight. Very good climbing abilities are known with these caterpillars.
White color is specific to the adult female moth while males have a darker appearance and a light brown color.
13. European Corn Borer
European Corn Borers (Ostrinia nubilalis) are widespread moths on Ohio crops.
They have a yellow color or a bright brown color with dark brown banding on the forewings.
As the name of the species suggests, European Corn Borers impact corn crops.
They bore into the leaves of corn which stops proper photosynthesis. The stalk is also impacted by the species which stops the proper flow of nutrients.
European Corn Borer Caterpillars are the ones responsible for corn damage to the species.
A dark yellow to brown body is specific to the caterpillar which also has a contrasting dark brown or black head.
European Corn Borer populations increase their numbers across the state as they like heat and dwell on temperature rises caused by climate change around the world.
14. Asian Long-horned Beetle
The Asian Long-horned Beetle (Anoplophora glabripennis) is an invasive species in Ohio.
It has a black color, long antennae, and an elongated body. This species is native to China and to parts of Korea where it’s not a pest.
In North America, Asian Long-horned Beetles are highly dangerous as pests to trees.
It feeds on trees and it burrows in the bark to lay eggs. Damages to many types of Ohio trees are noted in urban environments.
It’s believed the impact of the species across other states is also significant. Up to one-third of United States urban trees can suffer and even be killed by these black invasive beetles.
The species can be seen crawling or flying. However, it can only fly over short distances.
15. Walnut Twig Beetle
The Walnut Twig Beetle (Pityophthorus juglandis) is one of the invasive species also spotted in Ohio. This beetle is responsible for higher ecosystem damages in other states such as Tennessee but it can still impact local black walnut.
It’s believed it’s not the species itself that kills walnut but a fungus associated with the species.
Geosmithia morbida is a type of fungus that eats the leaves of walnut and that’s always present with these beetles.
Damages to walnut can be considerable. Since it takes years to even produce walnuts, these trees might not ever reach maturity and fruit production stages when impacted by these beetles.
16. Emerald Ash Borer
The Emerald Ash Borer (Agrilus planipennis) is an invasive species in just about all of the ranges outside of its native areas.
You can identify the bug by its elongated body and its metallic green color. It lay eggs directly in tree bark.
Once emerged, it starts eating and damaging the tree under the bark, so not highly visible at first.
Various species of ash trees can be impacted by the Emerald Ash Borer.
Areas of the state where this species is confirmed can enter quarantine. This is a stage that prevents ash sales to stop the spread of the species.
17. Hemlock Woolly Adelgid
These small white invaders (Adelges tsugae) are found in Northwestern and Northeastern US territories. They are confirmed in Ohio.
Eastern hemlock, Western hemlock, and Carolina hemlock are among the impacted species of the adelgid.
You can identify it by the clumps of white mass on the hemlock but no particular action is needed against the species.
Various types of natural predators eat these wooly adelgids reducing and eventually eliminating them before they turn into a serious problem to hemlock.
The species can also kill hemlock. Most recent data suggests the highest number of killed hemlock trees by the species are found in Southern parts of The Appalachians.
18. Rusty Crayfish
Rusty Crayfish (Orconectes rusticus) are native to many Ohio areas but are a problem for non-native fish.
Many types of non-native fish aren’t accustomed to facing these crayfish which means they end up killed.
This is a species that has been studied and certain chemicals that only kill these species have been developed.
Introducing the species in public waters is prohibited. Even fishermen aren’t allowed to use Rusty Crayfish as bait.
The highest impact of this crayfish is on other types of crayfish as they fight for the same resources. Some species of crayfish have even been eliminated in the areas they live.
Invasive Plants in Ohio
Plants are some of the most problematic invasive species in Ohio. They can be found in gardens, on crops, in woodlands, or on open land at all altitudes.
1. Chestnut Blight
This species of fungi (Cryphonectria parasitica) has been introduced to North America more than a century ago. Its damages are considerable and irreparable.
Chestnut Blight is a type of fungus that affects many types of local chestnut trees.
It doesn’t appear on healthy trees as it uses the wounds of trees to make its way under tree bark.
Some of the first signs of potential infection with the fungus for your chestnut include a yellow to brown area on the bark, often in the form of stripes.
It’s believed the fungus may have an Asian origin. Early reports have this species of fungi found on Chinese Chestnuts.
Soil has been used to kill the fungus. Some people wrap soil around infested trees to save them from fungi.
2. Dutch elm disease
Dutch elm disease (Ophiostoma ulmi) is a type of fungus that kills elm trees. North America and Europe are some of the most affected areas.
In Ohio, the species can be as detrimental as in other parts of the world.
The fungus gets inside trees through wounds where it may even overwinter before spreading and killing the tree.
The first areas of the tree where it spreads are its wounded or dying branches.
Elm trees in woodlands are highly impacted by fungi. Multiple municipalities have also planted elm trees for decoration and shade and now deal with a growing problem of dying trees.
One of the methods to spread its growing habitat is to break root connections of nearby infested elm trees.
3. White Sweet Clover
White Sweet Clover (Melilotus albus) is one of the invasive plants in the state and many other US states.
This is a type of wild bean plant rich in nectar. Bees and wasps are often seen feeding on their nectar.
However, the plant can be spotted on various crops such as Lucerne and invade them to the point they can’t grow properly anymore.
White Sweet Clover has very high resilience. Its seeds can survive in the ground for more than 20 years which makes it highly problematic if not removed.
Ohio meadows and riparian areas in the state are some of the habitats where this species can spread quickly as there are no direct management solutions in these areas as opposed to crops.
Seen as a weed in many parts of the state, White Sweet Clover starts its germination in the spring.
4. Multiflora Rose
Multiflora Rose (Rosa multiflora) is an introduced species in North America. It was introduced in Asia in a land conservation effort.
It has also been grown as a property limit type of plant as it has rapid growth rates.
This species is now considered an invasive plant in Northern and Northeastern habitats where complete elimination is difficult.
Multiflora Rose cannot be simply pruned as it tends to grow back vigorously. It needs to be removed from its roots, which makes management difficult.
Also known as the Japanese rose, Multiflora rose can grow to a tall height of up to 16 feet if left unmanaged.
This plant is also known to have some edible parts.
5. Common Buckthorn
Also known as Purging Buckthorn, this (Rhamnus cathartica) is an invasive small tree in Ohio.
Originative from Europe, the species has been introduced to North America for its visual appeal. It has been planted in parks and gardens but it may also be found on its own in cities.
The Common Buckthorn is an invasive species because its roots grow faster than the roots of native plants and because it overcrowds the soil with its multiple roots.
Furthermore, the species is also toxic. Both its leaves and its small fruits are toxic.
When eaten by birds, these leaves and fruits have a laxative effect on them but they don’t kill birds.
The best way to get reed of the species is to remove it with its roots but birds disperse their seeds regardless.
6. Autumn Olive
Autumn Olive (Elaeagnus umbellata) is a type of small tree or shrub that grows to a maximum height of up to a few feet.
It makes small red fruits, not olives. Its fruits may sometimes be used in products that taste like a tomato as tomato flavoring replacements.
The invasive nature of the species is given by its aggressive widespread distribution.
It can grow in areas with plenty of vegetation but it spreads even quicker on bare land, particularly on crops.
You can identify Autumn Olive trees in your garden by their long green leaves and small numerous white and yellow flowers.
Completely removing it is difficult as the seeds that fall onto the ground might survive your efforts of clearing the area, even when burning the land.
7. Japanese Knotweed
This type of knotweed (Fallopia japonica) has a different status in its history. It can be seen as a regular plant in some areas and an invasive species in other areas.
It grows into vines or remains a small shrub plant, depending on its vigor.
This is a species that covers much of the state and even the Northern Hemisphere.
Known as bisexual plants, Japanese Knotweed shrubs don’t need pollinators and can multiply rapidly.
Some species of moths and butterflies in Ohio and Northeastern US territories are known to rely on Japanese Knotweed as a host for caterpillars.
These caterpillars absorb the toxins of the plant to develop an unpleasant taste for possible predators.
8. Creeping Thistle
Creeping Thistle (Cirsium arvense) has an invasive status in different areas, including its native Ohio.
This is a type of thistle many butterflies and moths feed on.
However, the species can contaminate different types of crops, especially grains.
Its role as a herbaceous plant in this case includes maximizing resources such as water absorption which reduces the vigor of nearby grains.
Luckily, a creeping thistle can be managed with agricultural machinery without requiring chemical use.
It’s believed repeated cuts eventually kill this plant in a matter of years. These cuts need to be done before the flowering season of the creeping thistle.
Once the flowers open, wind, birds, and butterflies start spreading the seeds eventually leading to the quick spread of the herbaceous weed.
9. Tree of Heaven
Tree of Heaven (Ailanthus altissima) is one of the invasive species of trees in the state.
China is believed to be its native area and the species is now present in Ohio and across the East Coast.
As one of the tallest trees in the state, the Tree of Heaven can be used for wood.
However, its roots multiply quickly and spread deep in the ground taking away the resources of other plants.
Tree of Heaven always grows now and grows basal shoots all the time. It multiplies itself easily.
This tree can live for a century which means it does survive a long time for a noxious weed even if it doesn’t multiply itself in an area.
Initially planted as decoration, the Tree of Heaven soon became a problem in North America with its suckering characteristics.
10. Purple Loosestrife
Purple Loosestrife (Lythrum salicaria) is so accustomed to Ohio that it now spread on its own at rapid rates.
The high multiplication rate in a short area leads to low ecosystem diversity as it kills most other plants.
This type of plant also grows along rivers, destroying natural ecosystems.
A plant used in traditional medicine, Purple Loosestrife also has a positive role in the ecosystem as food.
The species is seen as a nectar-rich species for some types of Ohio bees.
Research on controlling this plant has been underway for almost half of a century. It turns out beetles that eat plants are its biggest enemies and some of the easiest biological control methods of the plant.
black-margined loosestrife beetle is used against the Purple Loosestrife.
11. Japanese Honeysuckle
This type of honeysuckle (Lonicera japonica) comes from Asia. It was introduced to the state and other states as a solution against soil erosion.
It was also grown on property limits as an ornamental plant.
The Japanese Honeysuckle sometimes develops an invasive nature, especially in disturbed areas such as flooded areas or old farms.
It starts to grow vigorously in this area killing almost all of the plants that are at least as high as itself.
Hundreds of leaves grow over existing flowers and the ecosystem essentially stopping access to natural sunlight and killing every plant under it.
The species can be managed without chemicals in small areas. You need to cut it and remove it with its roots to eliminate it from an area.
12. Bush Honeysuckle
This type of honeysuckle (Lonicera maackii) comes from Western Asia and may also be known as the Amur honeysuckle.
Its presence is dangerous to the natural ecosystem of deciduous woodlands.
Growing vigorously, this type of honeysuckle eventually stops the growth of young trees and of small flowers that grow in woodlands.
If left unmanaged, it can even kill woodlands as it completely stops the regeneration of trees in deciduous woodlands.
This type of honeysuckle is also dangerous to humans as it attracts wildlife such as deer which eat it. Ticks that come with deer are easier to spread to humans as a result.
13. Wild Teasel
Wild Teasel (Dipsacus fullonum) likes to live in direct sunlight where the soil has good humidity. It may arise in gardens or parks.
Some of its habitats also include prairies and areas next to woodlands.
In Ohio, Wild Teasel is a well-known biennial plant. It only grows every second year. It spends one year in a rosette stage, which can be identified as ground-level green leaves in small groups.
This is a species that can be managed by hand in gardens and other small areas.
You can dig it up, together with its roots.
Managing a widespread Wild Teasel invasion is a bit more laborious and it requires extra tools such as potent herbicide use.
However, unlike in digging where the weed can be removed at any stage, herbicides only show maximum efficiency in their rosette year.
Alternatively, the invasive plant can also be cut by hand or with agricultural machinery.
It needs to be cut after flowering for maximum efficiency.
14. Cutleaf Teasel
Cutleaf Teasel (Dipsacus laciniatus) is one of the weeds of Ohio. It can tolerate different soils including those with high salt content.
This type of weed is known to grow tall and it shows good vigor around crops even if it’s associated with prairies more.
Cutleaf Teasel is also known as Prairie Teasel as they can overgrow prairies. One of the main risks here is the risk of creating a monoculture as it overgrows all other native plants.
Its risk is known in Northern states from Ohio to the East Coast but the Midwest is where the Cutleaf Teasel is prevalent.
15. Garlic Mustard
Garlic Mustard (Alliaria petiolata) is a type of overgrowing herb. Part of the mustard family, it has a widespread presence around the state.
Its role is detrimental through its overgrowing capacity and due to its toxins.
This is a species that released toxic gasses when cut.
Various species of moth and butterfly caterpillars feed on it to absorb toxins and get an unpleasant taste to potential predators.
This type of plant also has small white flowers which are known to smell bad.
Midges are among the flies feeding on these types of flowers.
16. Eurasian Water-milfoil
The Eurasian Water-milfoil (Myriophyllum spicatum) is one of the aquatic species that’s a known weed in Ohio.
It grows to a maximum size of up to 6 feet, multiplies quickly and it diminishes the natural habitat for many native fish species.
Its spread across Ohio and North America was rapid. Introduced just a few decades ago, this is a species now known to Ohio and other parts of the US as well as Canada.
17. Smooth Brome
Smooth Brome (Bromus inermis) is one of the common species in gardens, parks, prairies, and at different elevations.
This is a type of perennial plant that flowers in the spring and in the fall, with a rapid growth rate.
Its seeds are carried by wind and its dual flowering per season means there are more seeds to spread and a potential to become an invasive species in different habitats.
A second flowering period in the same year isn’t mandatory as this is influenced by the habitat of the Smooth Brome.
18. Reed Canary Grass
This type of tall grass (Phalaris arundinacea) often serves as a host for the caterpillars of various moths and butterflies.
It grows rapidly in various habitats, particularly in disturbed soils.
This is a species that can reach a height of up to 6 feet and which has rapid multiplication rates with associated monoculture risks.
The fibrous nature of this grass also makes it useful to some industries. It is often used to heat buildings as it turned into biomass.
19. Common Reed
Common Reed (Phragmites australis) is one of the tall plants that grow in damp soil or shallow water.
Its tall height and its rapid spread in these areas leave no room for other types of plants and ecological diversity.
The plant is sometimes believed to come from Europe but it’s a native species in most parts of North America.
Common Reed is difficult to eliminate as it tends to grow to the maximum available area in water or damp soil.
This species has some economic importance as it can be used as food or as an ingredient when cooked.
20. Narrow-leaved Cattail
Brackish habitats are among the most common places where the Narrow-leaved Cattail (Typha angustifolia) can be seen today.
This is a species that has high resilience once it grows in an area. It has deep roots which may never be dug out properly, at least by hand.
One of the major risks associated with this invasive species is that it grows tall and it populates small and large areas reducing resources needed for other plants to grow.
Some cultures around the world use parts of Narrow-leaf Cattail as food.
21. Brittle Naiad
The Brittle Naiad (Najas minor) is a species native to Europe and Africa.
It has made it to Ohio in the area of The Great Lakes. There are a few theories on how this invasive species got here.
Some say it came with other imported plants and was cultivated together in the state.
Other theories say this plant came in with cargo shipping. Regardless of how it’s made it to The Great Lakes, this species is still spreading through seeds.
This submersed species is identified by its green color and bushy appearance.
22. Crisp-leaved Pondweed
This type of aquatic plant (Potamogeton crispus) is also invasive in the area of The Great Lakes and other lakes in Northern states.
High resilience is specific to the species which grows in areas other local plants cannot grow.
It even shows resilience in extreme temperatures surviving freezing temperatures and quickly continuing to grow and spreading once the weather gets warmer.
One of the main risks associated with the species is its capacity to overtake local plants and clog canals and waterways.
This species of aquatic plant (Butomus umbellatus) is now a high risk in the area of The Great Lakes. It has a European and Asian origin as it’s believed it has made its way to North America from Israel.
This is a plant that needs an aquatic environment and its risks are associated with displacing local species.
Flowering-rush has very long green leaves and white flowers.
This species doesn’t require pollination to spread which means it can cover an area quickly.
A common sight next to lakes and ponds, this is a species with rapid growth and spread.
It prefers muddy terrains and it grows in shallow water at the edges of lakes.
The plant is also grown for decorative purposes in gardens and man-made ponds.