Although the exact origin of common prickly-pear in Australia is not known, it was introduced by early settlers and spread for use as hedges and as pot plants.
In the absence of predators and disease, by the mid-1920s it took over 24 million hectares (60 million acres) of farming and grazing country.
Research into controlling the problem was carried out under the direction of the Commonwealth Prickly Pear Board, established by the Commonwealth, New South Wales and Queensland Governments. The Commonwealth Prickly Pear Board scientists introduced many insects with varied success.
In 1926, larvae from the Argentinian moth Cactoblastis cactorum were released and within 10 years, the once-dense fields of common prickly pear lay rotting or had vanished completely.
- Australasian Gazette - Prickly pear infested areas of Australia (newsreel) [external link]
- Cactoblastis moth (Powerhouse Museum) [external link]