It is one of five species in the genus Cactoblastis that inhabit South America, where many parasitoids, predators and pathogens control the expansion of the moths' population.

[1] However, in other places such as Australia, it has gained favor for its role in the biological control of cacti from the genus Opuntia, such as prickly pear.

Recent work in South America has identified four genetically-structured[2] ecotypes of C. cactorum that infest different hosts and possess different larval morphology.

[6] The larvae of C. cactorum are caterpillars that start out with a pink-cream color and gradually become orange, with distinctive black spots or bands.

The gregarious larvae bore into the cactus pad through a single entry hole by chewing through the tough outer cuticle of the cladode.

[5][9] During this time, the female moth does not eat; she uses all of her energy to travel up to 10 kilometres (6 mi) in search of dense cactus patches for reproduction.

[5] Following introduction, Cactoblastis exerted an immediate effect on the agricultural community in South Africa, where it diminished the population of the spineless Opuntia species valued as "cattle fodder".

[11] In 1956, the moth was introduced to the Caribbean island of Nevis and successfully controlled a complex of native "prickly pear" cacti.

[10] Cactoblastis cactorum has spread across the Gulf to Mexico, where it was first discovered on Isla Mujeres, a small island off the northeast coast of the Yucatán Peninsula.

[10] It is unknown how the moth migrated to Mexico; speculated means of propagation include winds and hurricanes, unintentional transport by humans, or commercial trade.

Estimated stress factors in the moths' native community indicate that it is restricted to temperate climates, due to the incubation period of its larvae,[10] but host associations may also play an important role in determining spread.

[17] Models based on environmental tolerances predict that its eventual range limits in the United States are bound by Charleston, South Carolina, to the north and by California to the west.

Compared to male moths, females respond more strongly to volatile organic compounds emitted by the cacti, allowing them to best determine where to oviposit.

This is an area of great potential interest in the Southwestern United States and Mexico because we know little about how of the diversity of cactophagous insects that are found in the region might influence the spread of C. cactorum.

It has yet to be determined if these organisms that limit the growth of the Cactoblastis are host-specific enough to be introduced into affected areas as a method of biological control of the moth itself.

In this particular case, the moth also has high adult mortality rates which tend to push organisms towards semelparous reproduction.

[20] Many attempts are being made to halt the expansion of Cactoblastis cactorum in order to prevent further damage to Opuntia cacti across Central America and the Southeast United States, where the effect of the moth has been identified as the most dangerous to the native flora.

[21] The bacterium was discovered by a group of scientists working in a colonization facility in Tifton, Georgia, who were attempting to rear large colonies of the moth.

[21] In their efforts to produce a sterile variety of the moth to eradicate it from its introduced habitat, a unique strain of bacterium was discovered.

[5] This bacterium, when raised with the developing moth larvae, caused 100% mortality due to a combination of excreted exotoxins.

[21] The primary lethal exotoxin found in the guts of Cactoblastis cactorum after being exposed to Bacillus thuringiensis is referred to commonly as BtCc.

[12] Another possible control option being explored would utilize ants to serve in a mutually beneficial relationship with the Opuntia cacti.

By sea, new regulations by APHIS require livestock fodder in transit found with evidence of Cactoblastis cactorum to be destroyed, fumigated, or returned to its country of origin.

[5] One of the primary implementations proposed would be to create a sterile version of Cactoblastis cactorum that would serve to eliminate the westernmost population of the moth and push its current territory eastward.

[5] This method would create a generation of moths which is unable to reproduce and would slowly but effectively curb the spread of the species.

Crude methods such as these are being used in Louisiana to eliminate the presence of the moth in swampy areas and generally involve the heavy use of removal by chainsaw, hacksaw, or other mechanical chopping device.

Lastly, a big unknown in the study of Cactoblastis cactorum is how various Opuntia species may develop defenses in response to its invasion.

[citation needed] There is a monument commemorating eradication of Opuntia by the moth in a park by Myall Creek, in Dalby, Queensland, Australia.