How did cactus moths control prickly pear cacti in Australia?

In Australia, the cactus moth (Cactoblastis cactorum) was introduced from Argentina in 1925 as a form of biological control to manage invasive prickly pear cacti.12

The moth larvae effectively destroy the cactus plants by burrowing into them and consuming their tissue. This method proved highly successful; by 1933, the major cactus-infested areas were under control, and approximately 24 million hectares (60 million acres) of land were reclaimed from cactus thickets for use as plowland and pasture.321

While biological control is a valuable tool for managing invasive species, it is essential to approach such interventions with caution. Introducing alien organisms into new habitats carries the risk that these species may themselves become pests, underscoring the necessity for careful, rational management in all environmental efforts.1