biological control of the prickly pear cactus
This is the story of one of Australia's greatest agricultural innovations in biological control, so great that the people of Boonarga in Queensland built a memorial to a moth.
The prickly pear, an attractive flowering cactus with a delicious pear shaped fruit, was brought to Australian gardens from South America in the 1830s. It grew quickly and farmers used it to form very effective hedges to fence farmland. Unfortunately it also resisted drought and had no predators, so it spread very quickly. By 1900 the prickly pear covered most of Queensland's best grazing land.
In 1920 the Commonwealth Prickly Pear Board was formed to get rid of the cactus pest. Scientists were sent to the USA, Mexico and Argentina to find an insect that ate it in its native environment. They chose a moth called cactoblastis cactorum, whose caterpillar eats prickly pears, and released it in Australia in 1926. Within ten years the caterpillars had cleared 11 million hectares of prickly pear.
Who Did It?
Commonwealth Prickly Pear Board : research, introduction
Henry Tyron : entomologist
Prickly pear in NSW
L R Tanner
NSW Agriculture & Fisheries, Agfact P7.6.48, 1989.
calicivirus and biological control
description of the moth
species in Australia
Dept of Agriculture, Fisheries
and Forestry Australia
Nematodes for pest control