The Cactoblastis Cactorum Memorial in Dalby recognises the effect that the Cactoblastis Cactorum moth had on controlling prickly pear in south west Queensland.
The Memorial was erected by the Queensland Women's Historical Association on 27 May 1965, and is located in Marble Street, Dalby.
The front inscription reads "In 1925, Prickly Pear, the greatest example known to man of any noxious plant invasion, infested fifty million acres of land in Queensland, of which thirty million represented a complete coverage. The Dalby District was then heavily infested. The biological control investigation was undertaken by the Commonwealth Prickly Pear Board, the joint project of the Commonwealth, Queensland and New South Wales Governments. Early in 1925, a small number of Cactoblastis Cactorum insects was introduced from the Argentine by Alan Parkhurst Dodd, O.B.E., who was officer-in-charge of the scientific undertaking. They were bred in very large numbers and liberated throughout the prickly pear territory. Within ten years, the insects had destroyed all the dense masses of prickly pear. This plaque, affixed by the Queensland Women's Historical Association on Thursday, 27th May, 1965, records the indebtedness of the people of Queensland, and Dalby in particular, to the Cactoblastis Cactorum, and their gratitude for deliverance from that scourge".
