Home / Snout Moths (Pyralidae) / Cactus Moth (Cactoblastis cactorum)

Cactus Moth (Cactoblastis cactorum)

The cactus moth is most well known as a pest to all forms of the prickly pear cacti. It is a member of the snout moth family and originated from South America. Argentinian entomologist Carlos Berg first described this species in 1885.

Cactus Moth


Scientific Classification

  • Family: Pyralidae
  • Genus: Cactoblastis
  • Scientific Name: Cactoblastis cactorum

Description and Identification


The larvae begin as pink-cream, eventually turning bright orange-red marked with black spots or bands. The full-grown larva can reach up to 25-30 mm in length.

Cactus Moth Larvae



Once mature, the caterpillars go underground to pupate.

Adult Moth

Sexual Dimorphism: Present but not prominent.

Color and Appearance:

Forewing: When opened, they are grayish brown, marked with wavy lines and dark spots. When closed, the color and pattern remain unchanged, though fewer lines and spots are visible.

Hindwing: When opened, the semi-permanent hindwings appear whitish. When closed, the wings are barely visible.

Average Wingspan: 27–40 mm (females); 23–32 mm (males)

Flight Pattern: Erratic

Season: Dry periods starting from June


Females lay their eggs in the form of an “egg stick” that looks similar to a cactus’ spine and contains 30-50 eggs.

Cactus Moth Eggs


Quick Facts

DistributionNative: South America, including Argentina, southern Brazil, Paraguay, and Uruguay Invasive: Australia, India, Hawaii, South Africa, and some Caribbean islands
HabitatArid regions
Lifespan of AdultsFemales: 9 days
Males: 11 days
PredatorsAnts, parasitic wasps, and New World monkeys
Host PlantsPrickly pear cacti
Adult DietDoes not feed

Did You Know

  • Though a pest in most parts of the world it is found in, this moth is considered an important biological control agent in Australia, keeping the prickly pear population down.
Cactus Moth Image


Cactus Moth Picture


Leave a comment

Your email address will not be published. Required fields are marked *