Various species of birds, plants, and animals are invasive in Texas. Some of them come from South or Central America.
Many introduced species in the state have European or Asian origins as well.
The specific warm habitat in the state means many of the invasive species here are not found in other states North of Texas.
On the other hand, invasive species such as wild boars are known to be present in Texas as well as in many other US states.
Invasive Animals of Texas
The following animals have an invasive status either due to competing for resources with native species or for their negative impact on soil, plants, shrubs, and trees.
1. Zebra Mussel
Multiple river basins in Northern Texas are home to the Zebra Mussel (Dreissena polymorpha).
Introduced from Russia, this species is now present in most US states where it shows a high ecological and economic impact.
Zebra Mussels are filter feeders. They may reduce food availability for local mussels but they also clog water lines and public water filtering facilities.
Furthermore, these types of mussels are also known to carry avian diseases.
A very high multiplication rate is specific to Zebra Mussels. Females can lay up to 1 million eggs in their lifespan.
Eating Zebra Mussels is also not recommended as the species tends to absorb multiple toxins.
2. Wild Boar
Wild Boars (Sus scrofa) or wild pigs are one of the atypical invasive species in the state. They have been introduced in farms a few decades ago.
They have escaped and colonized the state in the wild. As competent swimmers, Wild Boars eventually even made it to Matagorda Island where they started to breed in even higher numbers.
These types of wild pigs are known to trample vegetation in their way. Excessive feeding habits also harm local shrubs and trees.
Wild Boars are also responsible for carrying multiple species of parasites.
These parasites have a limited impact on Wild Boar themselves but they have a large impact on other wild and domesticated animals they come in contact with.
Trichinella spiralis nematode parasite is one of the most common species spread by Wild Boars to pigs, animals, and humans.
Coypu (Myocastor coypus), Nutria, or The Pig Swamp Rat is one of the invasive species of Texas riparian areas.
It lives next to water sources where it burrows and impacts the local ecosystem.
A herbivorous species, Coypu has been introduced to North America for its fur.
This species started to damage local habitats and enter into conflict with other herbivorous species. It may also destroy property close to water.
Coypu is also a species that carries and spreads diseases-causing bacteria both to humans and to animals.
4. Asian Clam
Sediments in water inhabited by Asian Clams (Corbicula fluminea) are shown to change over time. This is the major environmental impact of this Asian-origin clam which may also be known as The Golden Clam.
This species feeds on algae and it may also reduce the availability of algae to many local species.
Asian Clam is among the top species in terms of rapid waterways spread among the invasive species in the state.
Ships bring in more Asian clams, mainly by accident or with water ballast.
This type of clam may be found on sandy bottoms in different areas of the state.
5. Red Imported Fire Ant
Red Imported Fire Ants (Solenopsis invicta) are known for their potent sting. These are species that may easily damage all types of crops.
They build large colonies in mounds. These mounds can appear on crops and damage fruit or vegetable-picking machinery.
Mounds of these ants are also known to break or damages irrigation systems on various crops such as that soy or corn.
Stinging Red Imported Fire Ants also reduce food sources for local ants. Citruses and corn are among the most common foods in the state.
6. Island Apple Snail
The American Canal is one of the areas where the Island Apple Snail (Pomacea maculata) has established.
Data on the exact appearance of the species in Texas is conflicting. Still, this species has no more than a few decades in the state where it currently sees rapid growth rates.
This species is known to be more adaptable than local snails. It displaces local snails through its rapid spread.
Island Apple Snails have also been linked to spreading multiple parasites which harm the local ecosystem further.
The Rat Lungworm parasite is one of the typical parasites spread by the snail.
7. Mediterranean House Gecko
The Mediterranean House Gecko (Hemidactylus turcicus) is now a confirmed lizard species in Texas and other Southern states.
This is a species known for its high aggression level and invasive status driving many other geckos out of their range.
Living in the same areas as humans, these lizards are a common sight at night, when they might enter homes attracted to light.
A lizard that makes noises, The Mediterranean House Gecko is further known for attracting bugs with its calls and eating them.
This species also shows very high aggression and cannibalism towards its own young, both in the case of females and males.
8. Shovel-headed Garden Worm
Shovel-headed Garden Worms (Bipalium kewense) are an invasive species in greenhouses across the state.
This species has an uncertain origin and it may also be known as The Hammerhead Worm or the Kew Worm as it was first identified in Kew Gardens, London’s Botanical gardens in the United Kingdom.
Believed to be of an actual Asian origin, this species feeds on the larvae of various bugs and vegetation, including potted flowers and other plants in the state.
9. Eurasian Collared-Dove
The Eurasian Collared-Dove (Streptopelia decaocto) is one of the invasive doves with rapid growth in the state.
This species is already established in most inhabited areas of the state where it may reduce the food available to local dove populations.
Of European and Asian origin, this type of omnivore dove tends to outcompete species such as mourning doves.
They are also highly adaptable being present around farms and food processing facilities, especially those handling grains.
10. European Starling
The European Starling (Sturnus vulgaris) is often considered one of the most impactful invasive species in the world.
Ranked among the most detrimental invasive birds, this species is found in Texas where it competes for nesting locations and food with local species.
Woodpeckers are one of the species outcompeted for nesting holes.
Purple Martins and other types of small birds are also often spread out or even eliminated from their native range by the adaptable European Starling.
11. Black Webspinner
This insect (Oligotoma nigra) is found in populated areas of Texas.
A highly invasive species, it spends most time hiding under logs, rocks, or in dense vegetation.
Its larvae are known to spin silk tunnels where they hide from predators.
These winged species come out at night to eat grass on the lawn as well as different types of plants you might have around the house and in the garden.
Palm trees are known as their preferred food source.
Most homes with palm trees might need pest control for the Black Webspinner which has made its way to North America with imported palms.
12. Brown Marmorated Stink Bug
The Brown Marmorated Stink Bug (Halyomorpha halys) is one of the most common bugs in Southern and Eastern US states.
An invasive status is mostly unknown when it comes to these shield-shaped brown bugs.
They have established large colonies on Texas farms, where control measures are mandatory to stop their impact.
Apples, corn, beans, and other types of fruits and legumes are impacted by the bug.
A long proboscis allows the species to pierce fruit or fruit, stems, or leaves to suck out the juiced. This makes fruit unpalatable.
The long proboscis also means these types of bugs may not be entirely deterred by pesticides.
13. Brown Widow
Brown Widows (Latrodectus geometricus) are some of the most notable venomous spiders in Texas.
They are now an invasive species spread around the Southwestern US territories.
Spiders of this genus are native to Zimbabwe. In the US, they have an invasive status as they enter conflicts with local species such as The Black Widow.
Brown Widow spiders displace Black Widow populations.
Even if it displaces one of the most venomous species in the state, Brown Widows are venomous themselves.
Its neurotoxic venom may affect people and cause different levels of pain and allergic reactions. These are part of a disease it spreads called latrodectism.
14. Asian Tiger Mosquito
First confirmed in North America in 1983, The Asian Tiger Mosquito (Aedes albopictus) is one of the common species to be found in the state.
This invasive biting species has a striped brown body with contrasting white marks which inspire its name.
It has been confirmed in Texas and it spreads North, slowly getting used to cooler climates as well.
Unlike native species of mosquitoes, Asian Tiger Mosquitoes also show high adaptability even in the most adverse conditions.
These mosquitoes spread regardless of the impact of industrialization. High temperatures caused by global warming also show no real impact on the mosquito to this day.
15. Diaprepes Root Weevil
These types of weevils (Diaprepes abbreviatus) are native to The Caribbean. The species has a distinct striped black and orange appearance and a confirmed invasive status in the US, including Texas.
It first spread to Florida where it’s mostly known as a species that feeds on citruses.
The weevils also feed on other types of decorative plants and even on legumes in Texas.
A serious pest, Diaprepes Root Weevil is a species that eats the roots of potatoes, citruses, strawberries, and sugarcane.
All of these crops are important for the economy of the state.
Various types of horticultural oil may be used to prevent its presence on crops.
16. Banana Cockroach
Banana Cockroaches (Panchlora nivea) are one of the fastest-growing species of roaches in Texas.
This is a species known to have a bright green color which may make it look friendly compared to brown cockroaches.
This species of roach is native to tropical and subtropical climates.
It spreads with fruits and legumes which it eats. Some of the first signs of an invasion include spotting their small brown nymphs.
Banana Cockroaches are rarely found indoors but they might gather in larger numbers under porch lights at night.
17. Dark Rover Ant
Dark Rover Ants (Brachymyrmex patagonicus) have dark brown to black coloring. They are now seen in Central areas of Texas as they spread from South America.
A nuisance pest, Dark Rover Ants may enter homes and they might build large colonies next to homes.
There’s no evidence to show there’s real damage incurred by the species.
Dark Rover Ants might still be found indoors as they are attracted to lights at night.
Some management techniques can be applied without considering harsh chemicals.
For example, Dark Rover Ants love high humidity. Reducing the watering frequency of lawns and plants around the house may help keep them away.
18. Southern Mole Cricket
This type of cricket (Neoscapteriscus borellii) is frequently heard calling during the night. Its calls are mostly directed toward flying females which may spot them easier.
Southern Mole Crickets are omnivorous but they favor insects and various legumes over ornamental plants for food.
This is a species that may eat different types of insects but it’s found on crops and in gardens where it eats kale, onions, or tomatoes.
Southern Mole Crickets are particularly harmful to soft fruits such as strawberries.
19. Red-streaked Leafhopper
Almost 30 counties in Texas have already confirmed the presence of these Asian-origin leafhoppers (Balclutha rubrostriata).
It has a green and tan bright color combination and it’s a serious pest on crops and of sugarcane.
This species also displaces other species that rely on sugarcane.
For example, Red-streaked Leafhoppers are most damaging to some of the insects that feed on grasses and sugarcane.
Invasive Plants of Texas
The following plants show the most invasive status across one or multiple regions of Texas.
Alligatorweed (Alternanthera philoxeroides) is a species found in aquatic and dry habitats around Texas. It grows densely and this creates a vegetation mat which is mostly responsible for its invasive threat.
The species is known for its capacity to disrupt natural water flow in streams it grows in or around.
It may also limit the oxygenation levels in the water. Alligatorweed may also displace local vegetation.
This species also grows from stems on the ground. It means it can reproduce itself quickly compared to local species.
The species may sometimes be prevented by planting extra local plants in the area you want to protect.
21. Annual Bastard Cabbage
Annual Bastard Cabbage (Rapistrum rugosum) is widespread around Texas. This is a species known to grow close to the ground and to take up large open or disturbed areas where other types of grass aren’t growing.
High resistance to pesticides is among the first reasons this species becomes invasive.
This type of invasive plant is also difficult to remove as it’s quite laborious to dig out.
Management techniques that aren’t so labor-intensive are mostly based on preventing its spread through planting local species.
Adding grass seeds on open land without vegetation is among the first measures to stop its spread.
22. Greater Periwinkle
Garden waste is one of the primary methods Greater Periwinkle (Vinca major) manages to spread around the state.
This is a type of vine with blue to purple flowers. It can be used as a decorative plant that climbs in gardens or around the house.
This plant should not grow next to trees or other plants as it tends to kill them by overgrowing its leaves and flowers so that there’s no more light reaching its host.
In Texas, Greater Periwinkle is a major threat in the wilderness in riparian areas. It’s here that it climbs vegetation and that the species also grows on trees such as oak.
23. Callery Pear
This type of pear species (Pyrus calleryana) is only starting to be seen as invasive across the state.
Its impact is mostly tied to limiting roots and the growth potential of other local trees.
Callery Pear is also difficult to remove.
This type of tree also has different benefits to its profile. For example, its distinct-looking wood is used in certain industries such as the manufacturing of high-end furniture or musical instruments.
24. Brazilian Vervain
Climate change allows the Brazilian Vervain (Verbena brasiliensis) to start growing outside of its native Southern American habitat.
This is a species now seen in Texas parks and gardens. Its purple flowers allow the plant to be used for décor.
However, the Brazilian Vervain shows the tendency to grow in other areas as well, not just in the area it has been planted in intentionally.
With the tendency to spread more than a native species, this plant might still be controlled by pesticides.
25. Chinese Parasol Tree
This type of ornamental plant (Firmiana simplex) has been established in Texas following its introduction as a tree for gardens and parks.
It grows to a height of up to 50 feet within a few years.
The species has multiple benefits in its native China where it doesn’t invade areas and where its wood may be used for musical instruments.
Chinese Parasol Trees are a type of aggressive weed by behaves outside of China.
This specie inhibits the growth of other local trees and plants, particularly in areas next to water.
26. Chinese Pistache
Chinese Pistache (Pistacia chinensis) is a type of invasive deciduous tree in Texas. The species has been introduced to Southern parts of North America based on its resilience and resistance to drought.
This is a wind-stopping tree, often planted on property limits as well as along roads.
In the fall, its leaves turn red and yellow before falling or they may even stay on the tree.
This species inhibits the growth of other types of local trees.
On its own, without any cuttings, this species may reach a height of up to 66 feet.
Chinaberry (Melia azedarach) is another type of imported tree that turns invasive in Texas.
It might be found in some of the aridest habitats of the state but it can also be seen next to homes, as a decorative shading tree.
Chinaberry may turn invasive due to its roots.
Still, some of the largest Chinaberry trees are known to be sold for their medium-density wood.
This type of wood is particularly useful in the furniture industry where it may replace more expensive types of redwood.
28. Chinese Privet
Chinese Privet (Ligustrum sinense) is among the introduced hedge species of the state.
Its range expands from Texas to Florida as it already covers wide habitats.
Small green leaves are specific to this species which also has dark blue to purple non-edible fruit.
These fruits may also be toxic when consumed in high amounts.
While widely used in gardens, this is a species that also has an off-putting fragrance.
29. Castor Bean
Red to green coloring is specific to Castor Bean plants (Ricinus communis).
These are invasive plants found across different habitats and may have been introduced in gardens as décor.
Castor Bean plants should be removed as they are highly toxic.
Eating even a few seeds of this plant may kill an adult person.
Even coming in contact with Caster Bean may be problematic. Some people might show mild allergic reactions or severe dermatitis after coming in contact with its leaves.
30. Chinese Tallow
Chinese Tallow (Triadica sebifera) is another Asian-origin species common in parks and gardens.
The tree is used for its rapid growth and the capacity to create shade in public areas.
It also has economic importance as the dewy sap of the tree is used to make soap and other gel-like products.
Chinese Tallow is also highly invasive. It spreads quickly in new areas and it always carries the risk of creating monocultures.
31. Common Dandelion
Common Dandelion (Taraxacum officinale) was imported to Texas and the US as a type of food crop.
This species is known for its multiple uses such as providing nectar for bees and insects.
The plant is even edible as some restaurants serve it in different ways.
Common Dandelion carries a highly-invasive risk as it spreads quickly. Moist areas in full sun with mild soil moisture promote its spread considerably.
32. Great Mullein
This biennial species (Verbascum thapsus) is among the common sights in some of the aridest and remote areas of Texas.
While not very difficult to remove, Great Mullein is an invasive species as its seeds survive for decades.
This species is easy to remove from crops and other disturbed lands which doesn’t make it a species of major concern.
Still, it tends to spread out quickly when left unmanaged.
Some health benefits are attributed to Great Muellein. Its plant extracts are used for issues such as colics.
33. Coral Bells
Coral Bells (Antigonon leptopus) are among the oldest invasive species in the state.
Much of the plant such as the seeds can be eaten. Its seeds are among the preferred eaten parts.
Coral Bells are often seen along roadsides in the state. Its tropical habitat has now expanded to Texas.
It can spread itself quickly through seeds. Furthermore, Coral Bells show high resilience and adaptability to long drought periods.
This type of root vegetable (Colocasia esculenta) is often used in smoothies and other healthy food recipes.
Its edible roots are blended but its large leaves are only ornamental.
The invasive status of the species is visible across the state and on most continents. This species spreads quickly and its very large and multiple leaves cover all shorter plants in its vicinity.
The spread of Taro stops photosynthesis for shorter plants nearby.
This species has rapid growth rates which may be quantified to an average of 10 inches per year.
35. Hop Trefoil
Hop Trefoil (Trifolium campestre) has a low invasive risk. This species is seen in open areas in full sun, next to woodlands, on disturbed lands, or in pastures.
The species is also used in agriculture as a means to protect the soil and to fixate nitrogen levels.
Removing it mechanically is considered easy as the plant doesn’t have the deepest roots.
The flower heads of the species look very similar to hop flowers and have a bright yellow color.
36. Field Bindweed
This species (Convolvulus arvensis) is a perennial type of vine. It can climb, but only to a height of up to a few feet.
White or pink flowers are typically seen on Filed Bindweed.
A non-invasive status is specific to the species in the wild. However, this vine may become invasive in gardens and on crops.
Areas that get regular watering for moist soils are known to trigger its rapid spread and its invasive profile.
Even more, its seeds might survive on dry soil for up to a few decades and then be activated by water.
37. Heavenly Bamboo
This type of plant (Nandina domestica) is known for growing clusters of small red fruit.
Heavenly Bamboo fruit is highly toxic to animals and humans. Livestock tends to be the most exposed to these toxins.
Small birds can even die after eating a few of these fruits.
The species is invasive but it generally grows at a very slow pace.
38. Tree Privet
This evergreen tree (Ligustrum lucidum) has a medium to tall height. In most areas, it may reach a maximum height of around 30 feet.
This Asian-origin species is only invasive in Texas and other Southwestern regions of the US.
It multiplies to a larger area than planned for when it comes to décor in parks and gardens.
Furthermore, the species remains a common choice for gardens as trimming can shape the tree differently according to training preferences.
39. White Horehound
White Horehound (Marrubium vulgare) is one of the multiple invasive plants thriving in disturbed areas of the state.
This species spreads out quickly. Grass cannot grow in the areas the species establishes itself.
Mechanical control measures such as cutting and digging are recommended against the species. Outside Texas, various species of moth help control White Horehound spread.
The plant also has a beneficial role as it can be turned into a refreshing drink with a peppermint-like flavor.
40. Johnson Grass
Cultivated fields are the main habitat of Johnson Grass (Sorghum halepense).
This makes the species one of the most problematic for pure economic impact alone.
This type of grass has deep roots and it quickly spreads across crops.
The result is that it overcrowds cultivated legumes. Left unmanaged, it can limit the amount of rainwater that reaches the roots of cabbage, soy, or corn.
Lower plant diversity is also attributed to Johnson Grass across some areas of the state outside crops.
41. Common Lantana
Common Lantana (Lantana camara) may be invasive in some habitats such as woodlands.
This species may grow to a height of 4-5 feet which makes it problematic when spreading on nearby trees or plants.
Common Lantana may grow on trees essentially covering them similarly to climbing plants.
The species may be managed by manual techniques, but these are laborious. Using pesticides is also recommended against the species.
42. Macartney’s Rose
This type of plant (Rosa bracteata) has an Asian origin. It has an invasive status in Texas where it has been introduced as a decorative species.
Yellow and white flowers are specific to Macartney’s Rise.
This invasive species should be monitored and not planted at all in areas with livestock due to its toxicity.
Macartney’s Rose may be prevented but only when pesticides are sprayed in the area in the spring.
43. Little Bur-Clover
Little Bur-Clover (Medicago minima) is a species that becomes invasive on sandy soils across the state.
Typically seen on sandy slopes, this is a species that spreads out quickly, growing similarly to a shrub.
White, yellow, or white and pink flowers are seen on it during the season.
The species may grow up to a width of 50 inches but it shows an invasive growth pattern despite being introduced to balance soil nitrogen levels.
44. Lilac Chaste Tree
Lilac Chaste Tree (Vitex agnus-castus) is one of the most common invasive lilac tree species in the state and Southern US habitats.
This is a species introduced with a similar purpose to traditional aromatic lilac.
However, it shows the tendency to overgrow an area to a high extent.
It has been linked to a high decline of native species in areas it grows in all around North America. Despite serving as food for wildlife, this species is most detrimental to plants, shrubs, and trees.
45. Persian Silk Tree
One of the invasive trees that survives drought periods is the Persian Silk Tree (Albizia julibrissin).
This species grows up to a height of 20-30 feet and it has pink or orange flowers.
Persian Silk trees are among the invasive species which may also die affected by various plant viruses, especially those impacting mimosas.
Flowers of the Persian Silk Tree are common nectar sources for local insects.
46. Musk Thistle
This type of thistle (Carduus nutans) is known for its pink rosette which appears on mature plants.
Generally short, Musk Thistle might grow up to a height of 9 feet.
The species is known for its preference for disturbed soils as well as for agricultural soils.
A major risk with the species represents its habitat on crops. Since it prefers neutral pH soils, Musk Thistle might be found on different crops.
The species is now a listed noxious weed in North America.
47. Perennial Ryegrass
Perennial Ryegrass (Lolium perenne) is a species native to Europe. This is a plant that grows on sandy soils as well as in riparian areas.
It has an invasive status in Texas as it competes for resources such as water and moist soil for its roots with other native species of plants.
This competition is typically won by Perennial Ryegrass which means local plants eventually die in its range.
A high capacity to regenerate following drought or extreme temperatures also places the species in front of other local plants.
48. Sweet Scabious
This type of wildflower (Sixalix atropurpurea) has an invasive species in Texas and a noxious weed status in other parts of the world.
Native to Europe, this type of weed is identified by its purple flower which grows individually on each stem.
Mostly seen on crops, this is a species that may limit the growth of legumes or various other species of local wildflowers.
Some of the highest risks with uncontrolled Sweet Scabious plants in the state are common to agricultural areas as this species shows a preference for terrains high in organic matter.
49. Quihoui Privet
Quihoui Privet (Ligustrum quihoui) is one of the species found in a few small habitats across Texas woodlands.
The species shows small green leaves which grow in hundreds on each stem.
The species grows on the forest floor and it brings the risk of invasion covering up entire soils and plants that may live or survive on the forest floor.
Commonly grown in gardens, this species also grows dark blue fruits that aren’t edible.
50. Common Hedge Parsley
Common Hedge Parsley (Torilis arvensis) has an introduced status in North America.
This is one of the invasive plants in Texas that has leaves of various sizes. These leaves are also covered in short white hairs.
Common Hedge Parsley can further be identified by its leaves which are curled up.
The species only shows an invasive status in aerated disturbed soil.
Small fruit with thorns is seen on the species. These can help cling to animals which helps disperse their seeds.
51. Chinese Photinia
This species (Photinia serratifolia) with long green leaves and the small fruit is seen across central and Northern areas of the state.
Chinese Photinia is drought-tolerant but they aren’t established in Southern parts of Texas.
Slopes on mountains as well as woodlands represent common areas for the species to be found on.
You may find this species in juniper oak as well as in mixed woodlands. It’s here that these plants invade local species stopping the habitat they can grow in and competing for sunlight.
52. Vasey Grass
Vasey Grass (Paspalum urvillei) is a type of noxious weed in Texas. This is a species that grows to a size of up to a few feet.
A perennial species, Vasey Grass is found in areas of medium to high moisture such as around streams, lakes, and rivers.
The highest risk associated with the species is a wide monoculture.
Once established, this species is difficult to remove. It also stops local types of grass and plants from ever growing back unless mechanically removed from their invaded area.
53. Yellow Sweetclover
Yellow Sweetclover (Melilotus officinalis) is one of the invasive species of plants in gardens across Texas. The species also lives next to roads as well as on pastures.
This species has a bitter taste and not all livestock are interested in eating it.
Yellow Sweetclover is among the top nectar-rich plants for different types of bees in the state.
Managing its invasive status is almost impossible in the wild as it grows in small numbers in scattered locations.
In parks and gardens, management techniques such as pulling are sufficient to completely remove each plant.
54. Giant Reed
A common species along local rivers, this type of invasive plant (Arundo donax) is known to modify the hydrology and the natural plants in riparian areas.
Often growing to a height of several feet, this tall invasive species eventually crows all native plants out of riparian areas.
Multiple local programs have been put forward to control its spread.
The complete removal of Giant Reeds or Spanish Reeds is difficult due to the high associated cost.
Furthermore, removing the species also means removing Reed Wasps, a rare species of wasps dependent on the plant.