Purple Loosestrife,

(Lythrum salicaria).

Photo Credit: U.S. Fish & Wildlife Service.

Non-indigenous invasive plants, animals, and disease organisms cause increasing harm to native species and significant economic losses by reducing productivity and foreclosing opportunities for beneficial uses of forests, croplands, rangelands, and aquatic resources.

In recent years, many species introduced decades ago have begun to spread rapidly in U.S. ecosystems and pose increasing threats to our Nation's lands and waters. 

West Nile Virus,

(Flavivirus sp.).

Zebra Mussel,

(Dreissena polymorpha) .

Photo Credit: Benson.

Saltcedar/Tamarisk,

 (Tamarix sp.).

Photo Credit: USGS WERC.

Bullfrog,

 (Rana catesbeiana).

Photo Credit: Bill Leonard.

USGS plays an important role in Federal efforts to combat invasive species in natural and semi-natural areas through early detection and assessment of newly established invaders, monitoring of invading populations, improving understanding of the ecology of invaders and factors in the resistance of habitats to invasion, and development and testing of prevention, management and control methods.

Jack Dempsey,

(Cichlasoma octofasciatum).

Photo Credit: Leo Nico.

South American Nutria,

(Mycastor coypus).

Photo Credit: C.C. Lockwood.

Hemlock Wooly Adelgid,

(Pseudoscymnus tsugae).