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The callery pear (bradford pear) is native is East Asia and was imported to the U.S. in 1908 and first sold commercially in 1961. Callery pear trees forms dense thorny thickets, produces flowers with an offensive odor, and produces large amounts of fruit that litter sidewalks. Additionally, the ‘Bradford’ cultivar is extremely susceptible to damage from storms due to branches having narrow crotch angles; these trees will also split under their own weight after 15-20 years of growth.

Citrus black spot was first discovered in Australia and was introduced to the U.S. in 2010. The means of introduction was possibly through the importation of unregulated and/or non-commercial infected fruit. Citrus black spot is a fungal disease of citrus that decreases yields by causing external blemished and premature fruit drop. 

English ivy is native to Europe and was introduced to the U.S. via the nursery trade. The earliest records of naturalization are from the 1870s. English ivy competes with native plants and can spread into tree canopies.

The Gambian giant pouched rat is native to African. It was discovered in Florida in 2004, but was first introduced in 1999. The rat was released by an exotic pet breeder. This species is a large rodent capable of becoming highly destructive to agricultural crops and native species and may also serve as a vector of several diseases.

Golden nematode was first discovered in Long Island, New York in 1941. It was possibly transported on military equipment returning from Europe after World War I. If left uncontrolled, the golden nematode is capable of causing a 100% loss in potato yields.

Hammerhead worm was first discovered in 1891. It was introduced by movement of infested plants and soil. These worms are predators of earthworms, could potentially impact agricultural, horticultural, and natural ecosystems

The Japanese beetle is native to Japan. It was first discovered in 1916 but was probably introduced around 1911. It was introduced possibly in the soil of imported ornamental plants. This beetle is a destructive pest of turf, landscape plants, and crops; adults feed on the foliage and fruits of several hundred species of trees, shrubs, vines, and crops, while larvae feed on the roots of grasses and other plants.

The New Guinea flatworm was first found in Florida in 2012. It's method of introduction is unknown, although land flatworms have been known to be introduced in the soil of imported plants. New Guinea flatworms are predators of land snails.

The northern giant hornet is native to Asia and was first detected in Washington State in 2019. It possibly was introduced through the illegal importation of live specimens for food and medicinal purposes. This hornet is a pest of honey bees that can cause the complete loss of colonies.

Oak wilt is a fungal disease of oaks that can rapidly kill susceptible species (particularly red oaks). The origin and means of the introduction of oak wilt are unknown. The disease was first discovered in 1942 and is currently only found in the U.S., but it may have originated in Mexico, Central America, or South America.

The pale cyst nematode is native to South America. It was first discovered in Idaho in 2006. It is a major pest of potatoes and related crops. Uncontrolled infestations can reduce crop yields by 80%.

Palmer amaranth is native to Southwestern U.S. and was first reported outside of its native range in Virginia in 1915, but was not a significant weed in the Southeast until the 1990s. This species is one of the most economically important weeds of corn, cotton, and soybean; some populations are resistant to glyphosate and other herbicides.

Red-bellied pacu is native to South America. Individual specimens have been caught since the 1960s, but no reproducing populations have yet become established in the U.S. This species was probably introduced through aquarium releases or fish farm escapes. The environmental impact is unknown.

Red-eared slider is native to the Mississippi River drainage. Throughout its nonindigenous range, this species is introduced primarily through pet releases and escapes since the 1930's. This species may compete with native turtle species, although despite its widespread occurrence little is known of the impact on indigenous ecosystems.

The spotted lanternfly is native to China. It was first detected in 2014 (but appeared to have been present in the U.S. for 2-3 years) and poses a serious economic threat to multiple U.S. industries, including viticulture, fruit trees, ornamentals and timber.

Spotted wing drosophila was first discovered in Hawaii in the 1980's and in the continental U.S. in 2008. It was possibly introduced in fruits imported from Asia. This insect is a pest of unripe berries and stone fruits capable of causing significant economic losses.

Sweet orange scab is native to South America. It was introduced to the U.S. in 2010, most likely through the movement of infected nursery stock. It's a fungus affecting the fruit of sweet orange and mandarin cultivars.

The tomato leaf miner was originally thought to be native to Central America, but now believed to have originated in Peru. This pest is not yet present in the United States. It may be transported through the fruit trade and it's impact caused yield losses of up to 100% in tomatoes.

The honey bee varroa mite was first detected in Asia and was introduced to the U.S. in 1987. It's means of introduction was via commercial transportation of infested bee colonies. The varroa mite is a serious worldwide pest of the European honeybee and is a major cause of colony collapses.

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