Asian Long-Horned Beetle
Anoplophora glabripennis
Where It Came From
In boxes of products from China packed with wooden packing materials, this deadly hitchhiker made its way to the United States.
Where It Invaded
The Asian long-horned beetle is a large insect that eats healthy wood in living trees.
Its Effect
Difficult to detect deep inside healthy trees, the beetles are not easily killed. The female burrows into the tree, lays eggs and the wormlike larvae hatch out and start eating wood. After a year and a half, the larvae pupate and become adults when they will leave the tree to mate. There are no natural predators to the Asian long-horned beetle because they come from China. Insecticides have proved useless because of how deeply they burrow onto the trees. So far the trees that it seems to prefer are hardwoods; maples, birch, ash and others. They have been found in New York City and Chicago. Experts estimate that they could threaten trees throughout the United States in just a few years time.
Solutions
The only protection so far has been to discover infested trees, cut them down and burn them.
Fire Ants
Solenopsis xyloni
Where It Came From
Fire ants were accidentally brought to the U.S. from South America in the early 1900s.
Where It Invaded
They started in Alabama and have spread so far to 14 states.
Its Effect
Black fire ants look like regular ants but are much meaner. They attack any animal or person that comes near them and can also wreck crops. Fire ants attack by biting down on their victim and stinging them over and over. Every time they sting, they shoot a poison into the wound that burns and blisters. It can cause an allergic reaction in some people that can be fatal. Fire ant attacks are especially dangerous for small children and pets. Fire ants are hard to control because they spread by flight. Winged ants fly to a new place, mate and the female becomes a new queen for a new nest. A new nest can grow to hold 300,000 ants!
Solutions
Fire ant nests can only be destroyed by killing the queen. This is not an easy thing to do, because when a nest is bothered, the worker ants will carry the queen to a new place to start a new colony. The only thing that has worked is to leave food for workers to take to the queen that has been treated with insecticide. Once the queen is dead, the colony can be poisoned safely.
Asian Ladybug
Harmonia axyridis
Where It Came From
Imported in the 1970s to eat aphids, the Asian ladybug did a great job saving the pecan orchards in the southeastern United States from the damaging pests.
Where It Invaded
But then they spread up the coast, eating hungrily as they went.
Its Effect
Soon they had eaten so many aphids that the ladybugs native to the U.S. started to go hungry. When ahpid numbers dropped, the Asian ladybugs then went on to eat the other ladybugs! It is now thought that the nine-spotted lady beetle might be extinct in its native home of New York.
Solutions
None yet!
Gypsy Moth
Lymantria dispar
Where It Came From
Originally brought to the U.S. in the late 1800s to see if they could be used to produce silk, they quickly escaped into the wild.
Where It Invaded
They are now found throughout the United States.
Its Effect
Within a hundred years, gypsy moths have spread and become permanent members of most northeastern forests. The caterpillars strip the leaves off of more than a million acres of trees every year. The adult moths lay 500-1,000 eggs in an egg mass, which will hatch in the spring when the trees are just starting to bud. Gypsy moths do not live in a web like the eastern tent caterpillar or webworms, but may swarm on the trunk of a tree. The caterpillars can be identified by 6 rows of red dots.
Solutions
Scrape eggs into soapy water and place a sticky band around tree trucks to stop caterpillars from getting up trees
Killer Bees!
(Africanized Honey Bees)
Apis mellifera (hybrid)
Where It Came From
Though they look like regular honey bees, African bees behave very differently. Originally imported into Brazil in the 1950s to try to increase honey production, many African bee queens escaped and mixed with local honey bee populations.
Where It Invaded
They spread northward up to 200 miles a year reaching the United States in the 1990s.
Its Effect
They were an unwelcome arrival. African bees are much more aggressive than honey bees and will react to a smaller disturbance with violent attacks. They have been known to chase people more than a quarter mile away from their nest. Hundreds of people have died from African bee attacks. All honey bees can sting and should be avoided, but African bees are especially sensitive to being bothered. Be careful out there!
Solutions
People have tried to solve the problem of these spreading dangerous bees by replacing the queen with the calmer European bee queen.
Water Hyacinth
Where It Came From
In 1884, the beautiful water hyacinth, a native flower of South America, was first seen in the U.S. at an ornamental plant exposition in New Orleans.
Where It Invaded
A visitor from Florida took a cutting and brought it home to their garden pond and within weeks found it had taken over the pond. Thinking only to get rid of the troublesome plant they pitched it into the St. John’s River. This began a battle that has raged for the last century to beat back this aggressive plant.
Its Effect
The water hyacinth grows at a remarkable rate. Floating on lakes, ponds, rivers, marshes, and other types of wetland habitats, it spreads with great speed forming thick floating mats of vegetation. This blocks light to the underwater environment preventing oxygen production needed for the life in all waterways. This resulted in dying lakes and ponds and rivers becoming impassable to boats.
Solutions
Concerned people tried to chop up or burn the plants only to find that each small piece started a new plant! They introduced grazing manatees, but the plants grew too fast. Finally, into the 1960s when water hyacinth had spread to several southern states, people started spraying it with herbicides. This did have a preventive effect, but at what cost to the water quality and life in and around the waterways? No one will ever know the true cost of this beautiful and dangerous plant. In the past 25 years, scientists have introduced a series of insects that feed on the water hyacinth in its native environment. Though this may eventually create a balance with the water hyacinth, people do wonder what other plants those newly introduced insects might like to eat?
Kudzu
Pueraria lobata
Where It Came From
Kudzu is a vine from Japan that was introduced to the U. S. in the late 1800s at a garden show.
Where It Invaded
It quickly spread throughout the southeastern states, where the weather was perfect for kudzu growth.
Its Effect
People discovered that animals would graze it. It grew fast along the ground, so could be used to help stop erosion. The government hired men to plant it wherever erosion was an issue. After a while, kudzu began to cause problems. It grew so fast -- a foot a day in summer -- that it began to grow over whole forests, killing trees by blocking their sunlight. It covered barns, houses, fences and power poles. People began to work on trying to control kudzu.
Solutions
They tried herbicides, but found most of them did nothing, while some are thought to actually help kudzu grow. Now people raise goats to eat back the plant. They use kudzu vines to weave baskets, make paper and even hay. There is no easy way to get rid of kudzu. In the summer, people actually close their windows to keep the vine from invading the inside of their houses!
Purple Loosestrife
Lythrum salicaria
Where It Came From
Purple loosestrife was brought to North America from Europe by early settlers who wished to bring a bit of home to their gardens in the New World. It is thought to also have been brought accidentally in soil that was used as ballast in early shipping.
Where It Invaded
It was brought over from Europe in the early 1800s, but has since spread throughout North America.
Its Effect
Purple loosestrife looks like a delicate spike of purple flowers but it is deceptively powerful spreading quickly in wetlands and choking out other native plant species, such as cattails, fish and waterfowl.
Solutions
Many organizations have joined together to try to stop the spread of purple loosestrife and even reclaim wetlands already damaged by this aggressive invasive species. They removed the plants when they are flowering in late June, July and early August before they drop their petals (and produce seeds).
In areas with a small number of plants, the flower stalks are cut before they go to seed – as each purple loosestrife plant can produce more than 2 million seeds every year. They can also be dug out and removed carefully so that their seeds are not accidentally spread in this process or the plants will grow back.
As purple loosestrife grows, its roots expand and spread and removing the plants becomes more difficult, because broken roots left behind can grow new plants.
Biological controls for purple loosestrife – plant eating insects – have been studied and after many years of trials were found safe and effective. In 1996, they were released – two species of beetles that eat the leaves and a species of weevil that bores into the roots and lays their eggs (the young will then hatch out and eat the roots). There is hope that this will help reduce the purple loosestrife slowly over time.
Zebra Mussels
Dreissena polymorpha
Where It Came From
Zebra mussels are freshwater clams that are invasive species thought to have come to North America in the 1980s from Europe and Eurasia.
Where It Invaded
Zebra mussels entered the waterways in the ballast water from ships coming up the St. Lawrence seaway into the Great Lakes from Europe. Attaching to boats, fishing nets, plants caught in boat propellers and the lake water itself, they spread quickly down the Mississippi River and up all the rivers that enter it. From there they traveled anywhere that boats went, making their way to inland lakes around North America.
Its Effect
Zebra mussels grow in clusters attaching to rocks, piers, boat hulls, and any hard surface. They can attach to and clog boat engines and water pipes. They are razor sharp so affect swimmers and shore animals. They attach to native mollusk populations (mussels and clams) and crayfish smothering them and taking over their habitat.
Solutions
People are urged to clean off their boat motors and hulls and wash down their equipment before moving their boats from lake to lake. Drying boats for a week before moving to another waterway will also help to prevent spreading the mussels.
Zebra mussels are a challenge to eradicate. Water specialists have used chlorine and potassium to kill them and created special filters to stop their spread up water pipes. Scientists have also developed a bacterium to use as a pesticide on zebra mussels in contained areas such as pipes and water storage areas. This has helped power plants and irrigation system clear them from their systems, but cannot be used in open lakes and rivers.
Phragmites
Phragmites australis
Where It Came From
Phragmites is found all over the world, so it has been difficult to pinpoint where it came from originally. There is some evidence that it did exist as a native plant in North America, but a more aggressive subspecies from Europe may have started its expansion into wetland habitats around the country.
Where It Invaded
Phragmites has invaded wetlands all over North America.
Its Effect
Phragmites grows fast and dense with reeds reaching fifteen feet tall. They crowd out native wetland species, such as cattails, and change habitats so that they becomes uninhabitable for the native wildlife. Their roots form thick mats that expand ten feet per season, blocking the surface from use by wildlife.
Solutions
Many measures have been taken to eradicate phragmites or prevent its spread. In small, newer colonies without expansive root systems, breaking stems and applying herbicides have helped. In larger colonies, a combination of fire, herbicides and lowering the water level has had an effect. Repeated mowing can help.
Sea Lamprey
Petromyzon marinus
Where It Came From
The Sea lamprey is native to the northern Atlantic Ocean and its freshwater tributaries in Europe and North America. Because its life cycle includes both freshwater and marine habitats, it travels inland to waterways. Sea Lampreys became an invasive species in the Upper Great Lakes when a canal was built between Lake Ontario and Lake Erie.
Where It Invaded
In the past, Niagara Fall had been a barrier that kept the lamprey from entering the Upper Great Lakes. With the development of the canals in the early 1920s and the subsequent boat traffic, the lamprey worked their way into Lake Heron, Lake Michigan and Lake Superior.
Its Effect
Sea lamprey affect fish populations by attaching themselves to the sides of large fish and sucking our their bodily fluids. They attack trout, whitefish, chubs and other game fish. The disappearance of these large game fish allowed the increase of smaller, less desirable species like the alewife, changing the ecosystem’s populations.
Solutions
The U.S. Fish & Wildlife Service have a control program for the lamprey in the Great Lakes including chemical “lamprocide,” barriers to block upstream migration and the release of sterile male lamprey that compete for food but produce no young. The combination of all these controls has led to a significant reduction in lampreys.
