Invasive species of New Zealand origin

Some species endemic to New Zealand are causing problems in other countries, similar to the way introduced species in New Zealand cause problems for agriculture and indigenous biodiversity.

Animals

 * The New Zealand mud snail (Potamopyrgus antipodarum) is an invasive species in many countries and has been present in Europe since 1859.
 * The New Zealand flatworm (Arthurdendyus triangulatus) is an invasive species in Europe where it preys on earthworms and degrades soil quality.
 * Weka (Gallirallus australis) were introduced to several islands south of New Zealand, including Macquarie Island in the 1870s, where the weka was utilized as a food source. However, despite their survivability against other predators to islands it is not native to, the weka became a pest by outcompeting prey against native birds, and is claimed to have contributed to the extinction of the Macquarie parakeet and a native species of land rail.  The weka population in Macquarie Island declined in the 1980s and was fully eradicated in 1988.

Plants

 * Taupata (Coprosma repens), also known as mirror bush, looking-glass bush, New Zealand laurel or shiny leaf, is a weed in Australia, Norfolk Island, South Africa and the U.S. (California and Hawaii).
 * Pohutukawa (Metrosideros excelsa), sometimes called the New Zealand Christmas tree, is an invasive species in South Africa.
 * The biddy biddy (Acaena novae-zelandiae) is declared a noxious weed in the American states of Hawaii, California and Oregon. It is also a problem plant in Northumberland.
 * New Zealand flax or harekeke (Phormium tenax) is an invasive species in St Helena, some Pacific islands and in Australia.
 * Pohuehue (Muehlenbeckia complexa), also called wire vine, mattress vine and several other common names, is naturalised in Western Australia. Although it is a valued garden plant, it can become a pest in suitable climates (e.g. San Francisco's Golden Gate National Recreation Area) if not contained.
 * Manuka (Leptospermum scoparium) and kanuka (Kunzea ericoides) were planted in Hawaii during the early 20th century and have infested several islands.
 * Ngaio (Myoporum laetum) forms dense thickets in coastal areas of Southern California and Mexico and is therefore a serious weed.