Azores

After escaping from hedges in the 19th century, sweet pittosporum (Pittosporum undulatum) now occupies 24,000 ha in the Azores, equivalent to 49 per cent of its forested area.

England

An Australian barnacle (Austrominius modestus) that arrived on ships decades ago thrives today in England, including in the Thames, and also on the continent. It displaces native European barnacles.

France

West of Paris, in the Forest of Rambouillet, drivers are warned by road signs to watch out for red-necked wallabies, the descendants of escapees from a wildlife park.

Germany

Black swans that escaped from captivity or were released have formed small breeding populations in Germany, Italy, Belgium and elsewhere in Europe, and Japan
as well.

Zambia  

Africa lacks native crayfish, raising questions about the impacts Australian redclaw crayfish (Cherax quadricarinatus) are having in Lake Kariba in Zambia, and in other African wetlands.

South Africa

Eucalypts are less invasive than many Australian plants, but in South Africa the river red gum (Eucalyptus camaldulensis) has spread along many watercourses.

Israel

Israel is one of many countries to have golden wreath wattle (Acacia saligna) as a weed, with infestations in many places including the Judean Mountains and near Jerusalem.

India

The Australian sugarcane planthopper (Perkinsiella saccharicida) has become
a pest in most countries that grow sugar cane, including India.

Japan

The redback spider (Latrodectus hasseltii) is a serious concern in Japan, where it has spread across much of the country, to the concern of residents.

Guam

The eastern dwarf tree frog or eastern sedge-frog (Litoria fallax), is tiny, but that didn’t stop it somehow reaching Guam and thriving there.

Vanuatu

Animals often undergo ‘ecological release’ when they establish somewhere new, and for the green and golden bell frog (Litoria aurea) that has included thriving in Vanuatu, which is hotter than its native New South Wales.

New Zealand

The Australian paper wasp (Polistes humilis) is one of the stinging creatures New Zealand has acquired from Australia, along with the redback and huntsman spiders.

Hawaii

When it was discovered in Hawaii a century ago, the common grass skink (Lampropholis delicata) was thought to be a native reptile.

Tahiti

In Tahiti, silvereyes released in the 1930s to colour the landscape now spread the seeds of the island’s worst weed, miconia, a South American tree that covers vast areas of damaged rainforest.

California

Vedalia beetle (Rodolia cardinalis) is a welcome Australian, taken to California in 1888 to feed on cottony cushion scale, an Australian sap-sucking bug.

Chile

Silver wattle (Acacia dealbata) is very weedy in Chile, but also a useful source of firewood.

Florida

A common paperbark tree (Melaleuca quinquefolia) can shed millions of seeds when it is killed, helping explain why it is southern Florida’s worst weed.

Jamaica

After escaping from a botanic garden, sweet pittosporum (Pittosporum undulatum) spread over 1300ha of montane tropical rainforest in Jamaica, benefiting from hummingbirds that pollinate its flowers and Jamaican orioles that spread its seeds.

Argentina

Trade in pot plants probably explains how the blue garden flatworm (Caenoplana coerulea) reached Argentina, one of many countries it has colonised.

Brazil

In the Atlantic forests of Brazil the piccabeen palm (Archontophoenix cunninghamiana) is fast becoming a weed, owing to a high seed output.

Greenland

The Australian spider beetle (Ptinus tectus) can survive winters in Greenland because it lives inside kitchens in stored foods.

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