The EPPO Panel on Phytosanitary Measures added the cactus moth (Cactoblastis cactorum) which attacks Opuntia species to the EPPO Alert List.
The EPPO Panel on Phytosanitary Measures added the cactus moth (Cactoblastis cactorum) which attacks Opuntia species to the EPPO Alert List.
Cactoblastis cactorum (Lepidoptera: Pyralidae – cactus moth)
Why: Cactoblastis cactorum (Lepidoptera: Pyralidae, synonym: Zophodia cactorum) originates from South America. So far, it has essentially been known for its use in successful biological control of invasive cacti. It was introduced from Argentina into Australia in the 1920s where it drastically reduced introduced Opuntia populations, so that large areas of land could be returned to agriculture. The same efficacy was obtained in Hawaii, India and South Africa. But C. cactorum also spread to other parts of the world, in particular south-western USA, where it became a pest, threatening indigenous and rare species of Opuntia. In Mexico where Opuntia are important plants, used for fruit production, fodder, scale rearing (Dactylopius coccus) for dye production, traditional medicine etc., C. cactorum is perceived as a very serious threat and measures are taken to prevent its introduction.
Where:
North America: USA (Florida (found in 1989), Georgia, Hawaii, South Carolina). In Mexico, there are unconfirmed records in Yucatan, but recent surveys gave negative results.
Caribbean: Antigua & Barbuda (Antigua), Bahamas, Cayman islands (Grand Cayman), Cuba, Haiti, Jamaica, Dominican Republic, St Kitts & Navis, Montserrat, Puerto Rico, Trinidad, US Virgin Islands.
South America: Argentina, Brazil (southern part), Paraguay, Uruguay.
Oceania: Australia (New South Wales, Queensland), New Caledonia
Africa: Mauritius, Saint-Helena (Ascension Island), South Africa, Tanzania. Introduced in Kenya for biological control in 1996 but establishment failed.
Asia: India, Pakistan (introduced but establishment is uncertain).
On which plants: Opuntia spp., not found on other genera of Cactaceae. In its area of origin, C. cactorum has been recorded feeding on almost all of the many Opuntia species belonging to the platyopuntia group (prickly pears). Following its introduction to other parts of the world, C. cactorum readily attacked other species (including O. ficus-indica).
Damage: Females lay eggs in linear masses (forming an ‘egg-stick’ resembling cactus spines). Larvae collectively burrow and enter Opuntia cladodes (or pads) through a single entry hole and feed gregariously inside them. During feeding, frass is pushed out of the cladode and forms a noticeable heap on the ground. Larval feeding can also led to decay and rotting. High populations can kill the plants. Larvae are initially pinkish-cream coloured with dark red spots on the back of each segment. Later instars become bright orange, and dots expand and coalesce to become a dark band across each segment (mature larvae are approximately 25-30 mm long). Larvae then normally pupate in white cocoons amongst ground debris. Adults (wingspan about 22-35 mm) have greyish-brown forewings and white hindwings with some grey terminally. In Australia, there are two generations per year.
Pictures can be viewed on Internet:
http://www-staff.mcs.uts.edu.au/~don/larvae/pyra/cactor.html
Dissemination: Adult can fly. Over long distances, trade of infested Opuntia plants and transport on vehicles (adult moths are attracted by light) can ensure dissemination of the pest. It is suspected that it was introduced into Florida on imported nursery plants from Dominican Republic.
Pathway: Opuntia plants for planting from countries where C. cactorum occurs. It has been intercepted in USA on commercial imports of vegetative material for propagation.
Possible risks: Around the Mediterranean Basin, O. ficus-indica is widely present and used for fruit production or animal feed during dry periods. It is usually not cultivated as a regular commercial crop but planted as fences, windbreaks and round gardens. However, there are significant plantations in Italy, Spain and Israel for fruit production. If Opuntia spp. are regarded as invasive species, C. cactorum is indeed an efficient biocontrol agent, but if Opuntia spp. are considered as important crops or parts of the natural flora (protection against soil erosion, shelter for wildlife in arid regions etc.), C. cactorum may present a serious threat to Mediterranean countries. Data is lacking on establishment potential, but experience has shown that C. cactorum succeeded in most areas where it was introduced. So far, no efficient control methods are available.
EPPO RS 2003/101
Panel review date - Entry date 2003-07
Sources
Hernandez, L.R.; Emmel, T.C. (1993) Cactoblastis cactorum in Cuba (Lepidoptera: Pyralidae: Phycitinae). Tropical Lepidoptera, 4(1), 45-46 (abst).
Johnson, D.M.; Stiling, P.D. (1996) Host specificity of Cactoblastis cactorum (Lepidoptera: Pyralidae), an exotic Opuntia-feeding moth, in Florida. Environmental Entomology, 25(4), 743-748.
Mahr, D.L. (2001) Cactoblastis cactorum (Lepidoptera: Pyralidae) in North America: a workshop of assessment and planning. Florida Entomologist, 84(4), 465-473.
Mayra Perez-Sandi, C. (2001) Addressing the threat of Cactoblastis cactorum (Lepidoptera: ¨Pyralidae), to Opuntia in Mexico. Florida Entomologist, 84(4), 499-502.
Zhang, B.-C. (1994) Index of economically important Lepidoptera. CABI, Wallingford, UK, 599 pp.
Zimmermann, H.G.; Moran, V.C.; Hoffmann, J.H. (2001) The renowned cactus moth, Cactoblastis cactorum (Lepidoptera: Pyralidae): its natural history and threat to native Opuntia floras in Mexico and the United States of America. Florida Entomologist, 84(4), 543-551.
INTERNET
CSIRO web site – Systematic names: Cactoblastis cactorum (Berg). http://www.ento.csiro.au/aicn/system/c_2755.htm
NAPPO Pest Alert. Cactoblastis cactorum (Berg) 1885. Cactus moth threatens Mexico and the American Southwest. http://www.pestalert.org
The Nature Conservancy. Wildland Invasive Species Team. Invasives Alert ! Cactoblastis cactorum (Cactus moth). http://tncweeds.ucdavis.edu/alert/alrtcact.html
Tous, J. and L. Ferguson. 1996. Mediterranean fruits. p. 416-430. In: J. Janick (ed.), Progress in new crops. ASHS Press, Arlington, VA. http://www.hort.purdue.edu/newcrop/proceedings1996/V3-416.html
University of Florida. Featured Creatures – Cactus moth. http://creatures.ifas.ufl.edu/bfly/cactus_moth.htm