CACTOBLASTIS MEMORIAL CAIRN

A cairn was erected in Marble Street in 1965 to record the indebtedness of the people of Queensland (and Dalby in particular) to the Cactoblastis Cactorum. This tiny moth saved the Darling Downs from infestation by an introduced plant, the Prickly Pear.

A single, yellow flowering prickly pear was brought to Australia in 1839. By 1925 over 50 million acres of land in Queensland and New South Wales were covered with prickly pear, the greatest example known to man of any noxious plant invasion. The Dalby District was then heavily infested. It was impossible to effectively eradicate the weed either by sprays or cultivation. The land was rendered unusable and drove many from their farms.

The first eggs of the Cactoblastis Cactorum moth were imported from Argentina early in 1925 and were bred in very large numbers and liberated throughout the prickly pear territory. Within 10 years the insect had destroyed all the dense mass of prickly pear.

The cairn is located on Myall Creek as a lasting monument to the Cactoblastis Cactorum and its victory over the prickly pear menace.