Opuntia spp. are threatened by an infestation of the cactus moth (Cactoblastis cactorum) that has a distribution encompassing South Carolina southward along the coast to Florida and eastward along the Gulf of Mexico to Louisiana (Sauby et al., 2012: 562). The invasive moth feeds on species of the subfamily Opuntioideae. In Florida, infestation of C. cactorum was more typically on Opuntia stricta and Opuntia humifusa var. ammophila and may be related to their larger sizes and potential to release greater quantities of volatile organic compounds (Sauby et al., 2012: 566).

References

Sauby, K. E., Marsico, T. D., Ervin, G. N. & Brooks, C. P. 2012. The role of host identity in determining the distribution of the invasive moth Cactoblastis cactorum (Lepidoptera: Pyralidae) in Florida. Florida Entomologist 95: 561-568, available at: http://www.bioone.org/doi/full/10.1653/024.095.0304; accessed on: Nov 7, 2012.