Invasive Species - Cliff Lamere

Plants and animals which come from another country or state may grow and reproduce unexpectedly well in their new home. They can be a danger to the native plants and animals that have lived in that location for centuries. They are called Invasive Species because they are invaders. Invasive and invasion are very similar words.

NATIVE PLANT or ANIMAL - any plant or animal that occurs and grows naturally in a specific region or locality

Most invasive plants and animals are brought to the U.S. by man, sometimes on purpose, but at other times they are hidden in a transport vehicle (airplane, boat, automobile), or in a product that will be sold in this country.

1) If they have some quality in their own native land that would fill a need in the U.S., we bring invasive species to the U.S. on purpose. They are often not a bad pest in their own country, so we are surprised how much damage they can do here. [Plants may be raised in a nursery and then sold. Fish may be raised in a hatchery for sale.]

2) Invasive species may be unknown passengers on a boat (zebra mussels, Norway Rat)

3) Insects may travel in wood pallets or wood brought here to make pulp for newspapers

4) Insects or their eggs may hide on potted plants brought here to sell. Pests also can hide in the soil.

We may send different invasive species to foreign countries as often as they send theirs to us.

When a ship crosses the ocean, there is a danger that large waves may overturn the ship. When the ship has a cargo, it sits deep in the water and is stable. After the cargo has been delivered, the ship will sit high in the water. To correct this, the ship fills the cargo hold with water. If it is in a river or lake at the time, it will pick up freshwater that contains fish, algae, insect larvae (immature forms of insects), bacteria, etc. A ship's hold can contain as many as 3000 different kinds of living things in the water it takes in. The ship takes these organisms to the next port and dumps the water, releasing the possible invasive plants and animals before it loads its new cargo.

This has been a real problem in the Great Lakes. At present, the ships that intend to go to the Great Lakes must dump their freshwater ballast in the ocean and take in a saltwater ballast. The freshwater organisms they are carrying will die in the ocean, and most saltwater organisms will die in freshwater. But, not all. The Alewife, which probably swam its way through locks to get to the Great Lakes, is a problem saltwater fish that has adapted to freshwater.

An American ship carried the comb jellyfish, common along the Atlantic Coast, to the Black Sea in Europe where it has caused the total collapse of the fishing industry there.

When invasive plants and animals arrive, they find themselves in a new place that does not have the dangers they faced in their native land.

Plants leave behind the animals that ate them, the insects that injured them, the diseases that killed them, and sometimes poor weather or a poor climate that kept them from growing well. Other plants in their past environment may have competed with them. Animals leave behind similar problems. Once plants and animals arrive in a new country, the things that kept their growth slow may be absent from their new home. In that case, they may grow much better than the native plants and animals. They may even crowd out the native species.

Although invasive species were brought with the first explorers and settlers to North America, international trade between continents is much greater than ever before. And invasive species are arriving at an ever increasing rate. Many invasive species such as Zebra Mussels, Gypsy Moths, Dutch Elm Disease, and Golden Nematodes are beyond our ability to control them. We many never get rid of them.

COMMON NAME	TYPE	ORIGIN (where it came from, or where its native area is)	YEAR DISCOVERED IN UNITED STATES	SCIENTIFIC NAME
Eurasian Water Milfoil	aquatic	Europe, Asia, Africa	1942, Washington, D.C.	Myriophyllum spicatum
Purple Loosestrife	herbaceous	Eurasia	early 1800s	Lythrum salicaria
Tree-of-heaven	tree	Central China	1748	Ailanthus altissima
Common Reed, or Giant Reed Grass	herbaceous	unknown	prob. late 1800s	Phragmites australis
Water Chestnut	aquatic	unknown	1859	Trapa natans
Water Hyacinth	aquatic	Brazil	1884	Eichhornia crassipes
Garlic Mustard	herbaceous	Europe	1868	Alliaria petiolata
Kudzu	vine	Asia	1876	Pueraria lobata
Mile-a-minute	annual vine	Asia	1890	Polygonum perfoliatum
Giant Hogweed	herbaceous	Asia	early 1900s	Heracleum mantegazzianum

COMMON NAME	TYPE	ORIGIN (where it came from, or where its native area is)	YEAR DISCOVERED IN UNITED STATES	SCIENTIFIC NAME
Common Carp	fish	Europe, Asia	1877	Cyprinus carpio
Sea Lamprey	fish	Atlantic Ocean	Lake Ontario 1835	Petromyzon marinus
Alewife	fish	Atlantic Ocean	Erie Canal in 1860's	Alosa pseudoharengus
Zebra Mussels	mussel	eastern Europe	1988	Dreissena polymorpha
House Sparrow	bird	Europe	1853	Passer domesticus
European Starling	bird	England?	1890	Sturnus vulgaris
Gypsy Moth	insect	France	1868 or 1869	Lymantria dispar
European Elm Bark Beetle	insect	Europe	1930	Scolytus multistriatus
Japanese Beetle	insect	Japan	1916	Popillia japonica
Africanized Honey Bee, or Killer Bee	insect	Africa to Brazil to U.S.	1990	Apis mellifera
Asian long-horned Beetle	insect	Asia (China?)	1996	Anoplophora glabripennis
Red Imported FireAnt Imported Fire Ant (black)	insect	South America	1918 about 1930	Solenopsis richten Solenopsis invicta
Honey Bee Tracheal Mite	mite		1984	Acarapis woodi
Varroa Mite	mite		1988	Varroa destructor