Prickly pears in Australia

Prickly pears (Genus Opuntia) include a number of plant species that were introduced and have become invasive in Australia.

A monument to the Cactoblastis cactorum moth at Dalby, Queensland.

Prickly pear forest c 1930

Infestation of O. tomentosum 2019, near Yelarbon, Queensland

Prickly pears (mostly Opuntia stricta) were imported into Australia in the 19th century for use as a natural agricultural fence and in an attempt to establish a cochineal dye industry.[1] Many of these, especially the Tiger Pear, quickly became widespread invasive species, rendering 40,000 km² (15,000 sq mi) of farming land unproductive. The moth Cactoblastis cactorum from South America, whose larvae eat prickly pear, was introduced in 1925 and almost wiped out the population. This case is often cited[2] as an example of successful biological pest control.

There is a monument to Cactoblastis cactorum in Dalby, Queensland commemorating the eradication of the prickly pear in the region. The Cactoblastis Memorial Hall in Boonarga, Queensland, also commemorates the eradication.[3]