Invasive species are non-native species that have begun to spread outside their native habitat, where they may have no natural predators and none of the normal environmental controls which control their population. As a result, they often grow out of control, harming the local ecosystem and causing economic damage as well. This has become a problem all over the country, but in this article we’re going to learn about some of the more notable invasive species in North Carolina.
Let’s have a look!
9 Invasive Species in North Carolina
Scientific name: Myocastor coypus
Nutria, or coypu, are large rodents native to South America, particularly Argentina and Chile. They’re semiaquatic and their preferred habitat is freshwater marsh or swampland. They can weigh as much as 22 pounds and can eat a quarter of their body weight in vegetation in a single day.
Nutria are a highly destructive invasive species in North Carolina and much of the southern US. They reproduce with alarming speed and have few natural predators here, and the native plant life has not evolved to survive their feeding strategies. As a result, large swathes of vegetation can be wiped out in places where nutria have established themselves.
2. Fire Ant
Scientific name: Solenopsis invicta
Fire ants are so widespread and numerous in the southern US, including North Carolina, that most people don’t even realize that they’re an invasive species anymore. They’re native to South America, and likely spread to the US on cargo ships. In fact, they’re considered one of the worst invasive species in the world.
That’s because they’re almost impossible to get rid of- they’re tough, can survive a huge variety of environmental condition, and they reproduce and spread rapidly. With no natural predators, there are not environmental controls on the spread of their population. They quickly outcompete native species for the same resources, causing massive ecological disruption.
3. Wild Boar
Scientific name: Sus scrofa
Wild boars are the ancestors of the domestic pigs we raise for food, and they’re native to Europe, the Middle East, Asia, and northern Africa. They’re big, aggressive omnivores, and in their natural habitat they’re a favorite prey item of wolves, lions, and tigers, all of which are effective at controlling their population.
In North America, they have no natural predators, especially since wolves and cougars have long since been exterminated in the areas to which they’ve been introduced. Alligators rarely hunt them and there are no other native predators in these regions large enough to threaten them. They cause massive destruction by rooting up local plant life, which has not evolved to survive this kind of treatment, and they outcompete native animals.
4. Ambrosia Beetle
Scientific name: Trypodendron lineatum
A species of weevil, this beetle digs burrows in tree trunks in which they cultivate a fungus garden. This fungus is their sole source of nutrition. Trees in areas where these beetles are native have some resistance to the fungus and can survive this treatment. Many of the native conifers in North Carolina are less resistant, but they still tend to survive an infestation.
The real damage of the ambrosia beetle is economic. The lumber from trees infested by ambrosia beetles is either unusable or, in the case of less severe infestation, usable but far less valuable, resulting in monetary losses.
5. Emerald Ash Borer
Scientific name: Agrilus planipennis
This bright green beetle is native to Asia, where the females lay eggs in the bark of ash trees. The larvae then burrow into the the tree trunk and spend two years feeding on the tree underneath the bark. In Asia, it’s population density is too low to cause much of a problem, likely because of native predators keeping the numbers under control.
Outside it’s natuve range, with no native predators, the population can quickly grow out of control and devastate native ash tree species. It’s now spread across much of North America and it quickly kills green and black ash trees.
6. Zebra Mussels
Scientific name: Dreissena polymorpha
A small freshwater mussel native to the Black and Caspian Sea drainages, the zebra mussel spreads primarily through contaminated bilge water in cargo ships. It can also spread on recreational boats, which is likely how it has spread within the continental US.
Zebra mussels have no natural predators here and so they outcompete native molluscs easily. They tend to grow in water pipes and can clog them, causing a lot of damage.
Scientific name: Hydrilla verticillata
Also called waterthyme, hydrilla is an aquatic plant that forms dense underwater mats of vegetation. In Africa, Asia, and Australia, it’s part of the ecosystem and presents no problems. In North Carolina and the rest of the US, it’s a problematic naturalized invasive species.
It has a high resistance to salinity which allows it to grow in both salt and freshwater. It’s an aggressive species that outcompetes native aquatic plants and creates large swathes of monocrops, which results in a loss of biodiversity. It’s resistant to herbicides which leaves few methods of population control.
8. Tree of Heaven
Scientific name: Ailanthus altissima
Native to China, this tree has many commercial uses. Perhaps most important is it’s use as a host tree and food source for silkworms, thus making it critical to the silk industry. The wood from the tree is commonly used to make steamers, which are important in many Asian cuisines. It’s also popular as an ornamental plant, both because of it’s beauty and because of it’s tolerance for a wide range of growing conditions.
In both Europe and North America, it’s considered one of the worst invasive species ever introduced. It’s tolerance for various growing conditions means it can colonize nearly any environment, and it’s suckering ability means it can effectively clone itself indefinitely.
9. Autumn Olive
Scientific name: Elaeagnus umbellata
A large, flowering shrub native to Asia, autumn olive is an aggressive species that can colonize barren ground and establish an invasive colony with surprising speed. It’s been purposely introduced to many areas to stabilize the soil and aid in erosion control. Because it can fix atmospheric nitrogen in the soil, it can grow even in soils that most other plants would find unsuitable.