# 100 of the World's Worst Invasive Alien Species

100 of the World's Worst Invasive Alien Species is a list of invasive species compiled in 2000 from the Global Invasive Species Database, a database of invasive species around the world. The database is run by the Invasive Species Specialist Group (ISSG) of the International Union for Conservation of Nature (IUCN). The ISSG acknowledges that it is "very difficult to identify 100 invasive species from around the world that really are 'worse' than any others. ... Absence from the list does not imply that a species poses a lesser threat." In 2013, the ISSG updated their list to supersede the recently eradicated † rinderpest virus, and a few genus and species names were altered.

## Criteria for inclusion

Two criteria were used in selecting items for the list:
* An invasive species' "serious impact on biological diversity and/or human activities," and
* That species' "illustration of important issues surrounding biological invasion".
According to the ISSG, "only one species from each genus was selected." However, the renaming of Clidemia hirta now implies two Miconia species in the list.

## List of species

This list has been updated to reflect later changes in taxonomy, to ensure alphabetical order of genera, and to remove apparent errors. Common names may be ambiguous.
| Genus & species | Type | Common names | Notes |
| Acacia mearnsii | Shrub | Black wattle, Australian acacia | Invasive worldwide. Native to Australia. |
| Acridotheres tristis | Bird | Calcutta myna, common myna, house myna, Indian myna, mina, minah, mynah, talking myna | Invasive in Australia, Hawaii, Fiji and New Zealand. Established and potentially invasive in parts of Europe. Native to South Asia. |
| Aedes albopictus | Insect | Asian tiger mosquito, forest day mosquito, tiger mosquito | Invasive worldwide. Native to Southeast Asia. |
| Anopheles quadrimaculatus | Insect | Common malaria mosquito | Invasive in the eastern United States. |
| Anoplolepis gracilipes | Insect | Crazy ant, gramang ant, long-legged ant, Maldive ant, yellow crazy ant | Invasive in Australia, Hawaii, and Indian Ocean islands. |
| Anoplophora glabripennis | Insect | Asian long-horned beetle, starry sky beetle | Invasive in North America, and established and potentially invasive in parts of Europe. Native to East Asia. |
| Aphanomyces astaci | Pseudo-fungus | Crayfish plague | Invasive in Europe. Native to North America. |
| Ardisia elliptica | Tree | Coralberry, duck's eye, shoebutton ardisia | Invasive in tropical Australia, South Florida, the Caribbean, and many Pacific and Indian Ocean islands. Native to South and Southeast Asia. |
| Arundo donax | Grass | Arundo grass, bamboo reed, cane, cow cane, donax cane, giant cane, giant reed, reedgrass, river cane, Spanish cane, Spanish reed, wild cane | Invasive in California and New Zealand. |
| Asterias amurensis | Echinoderm | Flatbottom sea star, Japanese sea star, Japanese starfish, North Pacific sea star, Northern Pacific sea star, purple-orange sea star | Invasive in the southern coasts of Australia. Native to far north Pacific Ocean coasts. |
| Babuvirus Banana bunchy top virus | Virus | Banana bunchy top disease, BBTD, BBTV, bunchy top, bunchy top virus | Invasive worldwide. |
| Batrachochytrium dendrobatidis | Fungus | Amphibian chytrid fungus, "Bd", chytrid frog fungi, chytridiomycosis, frog chytrid fungus | Invasive in Australia, New Zealand, and Panama. |
| Bemisia tabaci | Insect | Cotton whitefly, silverleaf whitefly, sweet potato whitefly, sweetpotato whitefly | Native to India, invasive worldwide. |
| Boiga irregularis | Reptile | Brown catsnake, brown tree snake, brown treesnake | Invasive in Guam. Native to Wallacea, New Guinea, Melanesia, and Northern and Eastern Australia. |
| Capra hircus | Mammal | Domestic goat, feral goat, goat | Invasive worldwide. See also feral goats in Australia. |
| Carcinus maenas | Crustacean | European green crab, European shore crab, green crab, shore crab | Invasive in North America, Australia, parts of South America and South Africa. Native to Europe and North Africa. |
| Caulerpa taxifolia | Seaweed | Killer algae, killer seaweed | Invasive in the Mediterranean Sea. Native to the Indian Ocean. |
| Cecropia peltata | Tree | Faux-ricin, pumpwood, snakewood, trumpet tree | Invasive in Malaysia, Africa, and Pacific Islands. Native to tropical Central and South America. |
| Cercopagis pengoi | Crustacean | Fishhook waterflea | Invasive in Eastern Europe and in the Baltic Sea. Native to the Ponto-Aralo-Caspian basin. |
| Cervus elaphus | Mammal | Red deer, European red deer, western red deer, elk | Invasive in South America, New Zealand, and Australia. Native to Europe, Western Asia, and North Africa. |
| Chromolaena odorata | Herb | Bitter bush, camfhur grass, Christmas bush, common floss flower, devil weed, jack in the bush, Siam weed, triffid | Invasive in tropical Asia, Africa, and the Pacific. Native to Neotropics. |
| Cinara cupressi | Insect | Cypress aphid | Invasive worldwide. Native to Middle East. |
| Cinchona pubescens | Tree | Quina, red cinchona | Invasive in Hawaii, the Galapagos Islands, and Tahiti. Native to Central and South America. |
| Clarias batrachus | Fish | Clarias catfish, climbing perch, freshwater catfish, Thailand catfish, walking catfish | Invasive in North America. Native to Southeast Asia. |
| Coptotermes formosanus | Insect | Formosan subterranean termite, Formosan termite | Invasive in South Africa, Hawaii, and the United States mainland. Native to southern Japan, Taiwan, and South China. |
| Cryphonectria parasitica | Fungus | Chestnut blight | Invasive in North America. Native to East and Southeast Asia. |
| Cyprinus carpio | Fish | Common carp, Eurasian carp, European carp, fancy carp, feral carp, German carp, grass carp, Japanese domesticated carp, king carp, koi, koi carp, leather carp, mirror carp, Oriental carp, scale carp, wild carp | Invasive worldwide. Native to East Asia. |
| Dreissena polymorpha | Mollusc | Eurasian zebra mussel, wandering mussel, zebra mussel | Invasive in North America and Western Europe. Native to Eastern Europe. |
| Eleutherodactylus coqui | Amphibian | Caribbean tree frog, common coquí, coqui, Puerto Rican treefrog | Invasive in Hawaii, Virgin Islands, Dominican Republic, and Florida. Native to Puerto Rico. |
| Eriocheir sinensis | Crustacean | Big sluice crab, Chinese freshwater edible crab, Chinese mitten crab, Chinese river crab, Shanghai hairy crab | Invasive in Europe and North America. Native to East Asia. |
| Euglandina rosea | Mollusc | Cannibal snail, rosy wolfsnail | Invasive in Indian and Pacific Ocean islands. Native to the southeastern United States. |
| Euphorbia esula | Herb | Green spurge, leafy spurge, spurge, wolf's milk | Invasive worldwide. Native to Europe and temperate Asia. |
| Felis catus | Mammal | Cat, domestic cat, feral cat, house cat | Invasive worldwide. |
| Gambusia affinis | Fish | Gambezi, live-bearing tooth-carp, mosquitofish, mosquito fish, western mosquitofish | Invasive worldwide. Native to the fresh waters of the eastern and southern United States. |
| Hedychium gardnerianum | Herb | Ginger lily, kahila garland-lily, kahili ginger, wild ginger | Invasive in Hawaii and New Zealand. Native to Himalayas. |
| Hiptage benghalensis | Shrub | Hiptage | Invasive in Australian rainforests, Mauritius, and Réunion. Native to South Asia and Southeast Asia. |
| Imperata cylindrica | Grass | Blady grass, cogon grass, Japanese bloodgrass, speargrass | Invasive worldwide, including the southeastern United States. Native to tropical and subtropical Asia, Micronesia, Melanesia, Australia, Africa, and Southern Europe. |
| Lantana camara | Shrub | Angel lips, big sage, blacksage, common lantana, flowered sage, largeleaf lantana, prickly lantana, Spanish flag, West Indian Lantana, white sage, wild sage | Invasive worldwide. Native to the American tropics. |
| Lates niloticus | Fish | African snook, Nile perch, Victoria perch | Invasive worldwide. Contributed to the decline of haplochromines in Lake Victoria. Native to Africa. |
| Leucaena leucocephala | Tree | False koa, faux mimosa, faux-acacia, horse/wild tamarind, jumbie bean, lead tree, white leadtree, wild mimosa, wild tamarind | Native to Central America, invasive throughout other tropical regions. |
| Ligustrum robustum | Shrub | Bora-bora, Ceylon privét, Sri Lankan privet, tree privet | Invasive in the Mascarene Islands (Mauritius and Réunion). Native to South Asia and Southeast Asia. |
| Linepithema humile | Insect | Argentine ant | Invasive worldwide. Native to South America. |
| Lissachatina fulica (syn. Achatina fulica) | Mollusc | African giant snail, giant African land snail, giant African snail | Invasive in South Asia, Southeast Asia, East Asia, the Pacific, Indian Ocean islands, the West Indies, and the United States. Native to East Africa. |
| Lithobates catesbeianus | Amphibian | American bullfrog, bullfrog, North American bullfrog | Invasive in Central and South America, the Caribbean, Western Europe, and East Asia. Native to eastern North America. |
| Lymantria dispar | Insect | Asian gypsy moth, Asian spongy moth, spongy moth | Invasive worldwide. Native to East Asia. |
| Lythrum salicaria | Herb | Purple loosestrife, purple lythrum, rainbow weed, spiked loosestrife | Invasive worldwide. Native to Europe. |
| Macaca fascicularis | Mammal | Crab-eating macaque, cynomolgus monkey, long-tailed macaque | Invasive in Mauritius, Palau (Angaur Island), Hong Kong, and parts of Indonesia (Tinjil Island and Papua). Native to Southeast Asia. |
| Melaleuca quinquenervia | Tree | Broad-leaved paperbark tree, broad-leaved tea tree, five-veined paperbark tree, paper bark tree, paperbark tea tree, punk tree, white bottlebrush tree | Invasive in Florida. Native to New Caledonia, Papua New Guinea, and coastal Eastern Australia. |
| Miconia calvescens | Tree | Bush currant, purple plague, velvet tree | Invasive in Pacific Islands, including Hawaii and Tahiti. Native to rainforests of tropical America. |
| Miconia crenata (syn. Clidemia hirta) | Shrub | Clidemia, faux vatouk, Koster's curse, soap bush, soapbush | Invasive in Hawaii, Indian Ocean islands (Seychelles), peninsular Malaysia, and parts of Micronesia (Palau). |
| Micropterus salmoides | Fish | American black bass, bass, black bass, green bass, green trout, largemouth bass, largemouth black bass, northern largemouth bass, stormundet black bass | Invasive worldwide. Native to the eastern United States. |
| Mikania micrantha | Vine | American rope, bitter vine, Chinese creeper, climbing hemp vine, mile-a-minute weed | Invasive in the Pacific. Native to Neotropics. |
| Mimosa pigra | Shrub | Bashful plant, catclaw, catclaw mimosa, giant sensitive plant, giant trembling plant, mimosa | Invasive in Southeast Asia and Australia. Rice crop pest. Native to South America. |
| Mnemiopsis leidyi | Comb jelly | American comb jelly, comb jelly, comb jellyfish, sea gooseberry, sea walnut, Venus' girdle, warty comb jelly | Invasive in Southeast European waters, including the Black, Azov, Marmara, Aegean, and Caspian Seas. Native to temperate, subtropical estuaries along the Atlantic coast of North and South America. |
| Mus musculus | Mammal | House mouse | Invasive worldwide. Native to South Asia. |
| Mustela erminea | Mammal | Beringian ermine, ermine, Eurasian ermine, Eurasian stoat, short-tailed weasel, stoat | Invasive in New Zealand. Native to the temperate Northern Hemisphere. |
| Myocastor coypus | Mammal | Coypu, nutria | Invasive in North America, Europe, and Asia. Native to South America. |
| Myrica faya (syn. Morella faya) | Shrub | Candleberry myrtle, faya bayberry, fayatree, fire tree, firebush | Invasive in Hawaii, New Zealand, and Australia. native to the Azores, Madeira Islands, and the Canary Islands. |
| Mytilus galloprovincialis | Mollusc | Bay mussel, blue mussel, Mediterranean mussel | Invasive worldwide. Native to the Mediterranean Coast and the Black Sea. |
| Oncorhynchus mykiss | Fish | Baja California rainbow trout, coast angel trout, coast rainbow trout, coast range trout, hardhead, Kamchatka steelhead, Kamchatka trout, Kamloops, Kamloops trout, lord-fish, rainbow trout, redband, redband trout, salmon trout, silver trout, steelhead, steelhead trout, summer salmon | Invasive worldwide. Native to cold-water tributaries of the Pacific Ocean in Asia and North America. |
| Ophiostoma ulmi sensu lato | Fungus | Dutch elm disease | Caused destructive pandemics in Europe and North America. Native to Asia. |
| Opuntia stricta | Shrub | Common prickly pear, Araluen pear, Australian pest pear, common pest pear, erect prickly pear, gayndah pear, shell mound pricklypear, sour prickly pear, spiny pest pear | Invasive in South Africa and Australia. Native to Neotropics. |
| Oreochromis mossambicus | Fish | Common tilapia, Java tilapia, kurper bream, Mozambique cichlid, Mozambique mouth-breeder, Mozambique mouthbrooder, Mozambique tilapia | Invasive worldwide. Native to Southeast Africa. |
| Oryctolagus cuniculus | Mammal | European rabbit, wild rabbit | Invasive in Australia and New Zealand. Native to Southwestern Europe. |
| Pheidole megacephala | Insect | Big-headed ant, coastal brown ant | Invasive in Australia, New Zealand, and Florida. Native to Southern Africa. |
| Phytophthora cinnamomi | Pseudo-fungus | Cinnamon fungus, green fruit rot, heart rot, phytophthora root rot, seedling blight, stem canker, wildflower dieback | Invasive in Africa, Australia, Italy and North America. |
| Pinus pinaster | Tree | Cluster pine, maritime pine | Invasive in South Africa and New Zealand. Native to the Mediterranean Basin. |
| Plasmodium relictum | Protozoan | Avian malaria | Highly invasive in Hawaii; implicated in several bird extinctions |
| Platydemus manokwari | Flatworm | New Guinea flatworm, snail-eating flatworm | Invasive in Pacific islands. Native to New Guinea. |
| Pomacea canaliculata | Mollusc | Apple snail, channeled apple snail, golden apple snail, golden kuhol, miracle snail | Invasive in Southeast Asia and Hawaii. Rice crop pest. Native to South America. |
| Pontederia crassipes (syn. Eichhornia crassipes) | Aquatic plant | Common water hyacinth, eichhornia, floating water hyacinth, water orchid | Invasive worldwide. Native to South America. |
| Potamocorbula amurensis | Mollusc | Amur River clam, Amur River corbula, Asian bivalve, Asian clam, brackish-water corbula, Chinese clam, marine clam | Invasive in San Francisco Bay (United States). Native to coasts of China, Japan, Korea, and Siberia. |
| Prosopis glandulosa | Tree | Honey mesquite, Texas mesquite | Invasive in Africa and Australia. Native to Aridoamerica. |
| Psidium cattleyanum | Shrub | Cattley guava, cherry guava, strawberry guava | Highly invasive in Mauritius and Hawaii. Native to Brazil. |
| Pueraria montana var. lobata | Vine | East Asian arrowroot, Japanese arrowroot, kudzu, kudzu vine | Native to Southeast and East Asia. Invasive in several other parts of the world, especially the southeastern United States. |
| Pycnonotus cafer | Bird | Red-vented bulbul | Invasive in many Pacific islands. Native to South and Southeast Asia. |
| Rattus rattus | Mammal | Black rat, European house rat, roof rat, ship rat | Invasive worldwide; implicated in numerous mammalian, reptilian and bird extinctions. Native to Central Asia. |
| Reynoutria japonica (syns. Fallopia japonica, Polygonum cuspidatum) | Shrub | Asian knotweed, crimson beauty, donkey rhubarb, fleeceflower, German sausage, Japanese bamboo, Japanese fleece flower, Japanese knotweed, Japanese polygonum, kontiki bamboo, Mexican bamboo, pea-shooter plant, reynoutria fleece flower, sally rhubarb | Invasive in Europe, New Zealand, and North America. Native to Japan. |
| Rhinella marina | Amphibian | Bufo toad, bullfrog, cane toad, giant American toad, giant neotropical toad, giant toad, marine toad, Suriname toad | Invasive in Australia, Melanesia, the Pacific, Philippines, Taiwan, Florida, and the West Indies. Native to South America and Central America. |
| Rubus ellipticus | Shrub | Asian wild raspberry, broad-leafed bramble, Ceylon blackberry, golden evergreen raspberry, Molucca berry, Molucca bramble, Molucca raspberry, robust blackberry, wild blackberry, wild raspberry, yellow Himalayan raspberry | Invasive in Hawaii. Native to South Asia. |
| Salmo trutta | Fish | Blacktail, brook trout, brown trout, finnock, Galway sea trout, herling, lake trout, orange fin, Orkney sea trout, salmon trout, sea trout, trout, whitling | Invasive worldwide. Native to Europe, Central Asia, and the Atlas Mountains of Africa. |
| Salvinia molesta | Aquatic plant | Giant salvinia, kariba weed | Invasive worldwide. |
| Schinus terebinthifolia | Tree | Brazilian holly, Brazilian pepper, Brazilian pepper tree, Christmas berry, Florida holly, Mexican pepper | Invasive in North America, Australia, the West Indies, Pacific Islands. Native to South America. |
| Sciurus carolinensis | Mammal | Eastern gray squirrel, gray squirrel, grey squirrel | Introduced to the British Isles, Italy, and South Africa. Native to eastern North America. |
| Solenopsis invicta | Insect | Red fire ant, red imported fire ant, RIFA, | Invasive in Australia, New Zealand, Southeast Asia, the Caribbean, and the United States. Native to tropical South America. |
| Spathodea campanulata | Tree | African tulip tree, fireball, flame of the forest, fountain tree, Indian cedar, Santo Domingo mahogany | Invasive in Pacific Islands. Native to West Africa. |
| Sphagneticola trilobata | Herb | Creeping ox-eye, Singapore daisy, trailing daisy, wedelia | Invasive worldwide. Native to Central America. |
| Sporobolus anglicus (syn. Spartina anglica) | Grass | Common cord grass, cordgrass, rice cord grass, rice grass, spartina, Townsend's grass | Invasive in New Zealand. |
| Sturnus vulgaris | Bird | Common starling, English starling, European starling | Native to Eurasia. Invasive in North America, Australia, and New Zealand. |
| Sus scrofa | Mammal | Eurasian wild pig, wild boar | Invasive worldwide. Native to North Africa, Asia, and Europe. |
| Tamarix ramosissima | Shrub | Salt cedar, tamarisk | Invasive in the western United States and northern Mexico. Native to Eurasia. |
| Trachemys scripta elegans | Reptile | Red-eared slider, red-eared slider terrapin, slider turtle | Invasive worldwide. Native to southeastern North America. |
| Trichosurus vulpecula | Mammal | Common brushtail possum | Invasive species in New Zealand. Native to Australia. |
| Trogoderma granarium | Insect | Cabinet beetle, Khapra beetle | Invasive worldwide. Native to South Asia. |
| Ulex europaeus | Shrub | Gorse, Irish furze, whin | Invasive in New Zealand and Hawaii. Native to Western Europe and parts of Asia. |
| Undaria pinnatifida | Seaweed | Apron-ribbon vegetable, Asian kelp, Japanese kelp, sea mustard, wakame | Invasive in New Zealand, the United States, Western Europe, Argentina, Australia, and Mexico. Native to Japan. |
| Urva auropunctata (syn. Herpestes auropunctatus) | Mammal | Small Indian mongoose | Invasive on the northeast coast of South America, Croatia, Amami Ōshima, Fiji, Hawaii, and the West Indies; implicated in several mammal, bird and reptile extinctions. Native to South and Southeast Asia. |
| Vespula vulgaris | Insect | Common wasp, common European yellowjacket, European Wasp | Invasive in New Zealand, Australia, Chile, and Argentina. Native to the temperate Northern Hemisphere (Palearctic). |
| Vulpes vulpes | Mammal | Red fox, black or silver fox variation, cross fox variation | Invasive in Australia. Native to the Northern Hemisphere. |
| Wasmannia auropunctata | Insect | Cocoa tree-ant, electric ant, little fire ant, little introduced fire ant, little red fire ant, small fire ant, West Indian stinging ant | Invasive in the Pacific, the West Indies, and parts of Central Africa. Native to Central and South America. |