Cactus Moth, Cactoblastis cactorum, is native to Argentina, Paraguay, Uruguay and southern Brazil.
Life Cycle
Hosts include cactus species such as prickly-pear. The female lays a long chain of eggs at the end of a cactus spine. The resulting 'egg-stick' resembles the spine of the cactus. After hatching, the pinkish-cream colored larvae burrow into the pad of the plant. Larvae move in groups as they feed and also push the frass onto the ground, often forming significant piles. The space inside the plant is reduced to a green mass of goo as the larvae feed. As they grow, caterpillars become orange with dark red bands across each segment. Once mature, they are about 1-1.5 in. (2.5-3.8 cm) long. They leave the plant and form a white cocoon on the ground, either in a protected crevice of a nearby tree or just among the debris. The adult has a 1-1.5 (2.5-3.8 cm) inch wingspan with faint dark dots and lines on the light tan wings. At rest, its wings wrap around its body.
Distribution
It is known to be established in Florida, Georgia, and South Carolina. In Queensland, Australia, there are two generations per year. It is expected that development would occur faster in the warm climate of Florida.
Control Efforts
Attempts are being made to restrict the expansion of Cactoblastis cactorum to prevent further damage to Opuntia cacti across the Southeastern United States and Central America. Biological control using predatory wasps and bacteria are being researched. Mutually beneficial relationships with ants that already exist in some native cactus populations are being explored. Attempts to quarantine afflicted Opuntia in affected areas is also being practiced.