CACTOBLASTIS:  THE MOTH FROM SOUTH AFRICA THAT TURNED - H. G. Zimmermann

Helmuth Zimmermann & Associates, Faerie Glen 0043, South Africa

The cactus moth, Cactoblastis cactorum (Lepidoptera: Pyralidae) was introduced from South Africa to the Caribbean in 1957 to control rampant opuntia  invasions on British controlled territories, including Nevis, St. Kitts, Antigua and Grand Cayman. These projects were highly successful and farmers could again utilize their land for grazing. These successes lead to inadvertent and illegal introductions to other islands with similar opuntia invasions. Cuba also had problems with invasions of Opuntia dillenii and the cactus moth reached Cuba, either by natural dispersal or by an illegal introduction, in 1980. The outcome was generally welcomed by farmers.  Since then C. cactorum  spread (or was spread) to virtually all the islands in the Caribbean, with the exception of some remote islands in the Lesser and Dutch Antilles.  The detection of the cactus moth in Florida in 1989 triggered the first alarms and it has since spread rapidly, mainly along the Florida coasts, reaching South Carolina in 1999 and crossing over the Florida/Alabama border in 2005. Some scientists believe that C. cactorum has dispersed naturally by own means from the Caribbean, but there is very convincing evidence that it was introduced to Miami via infested nursery material. The Mexican Government, the USDA/APHIS and the International Atomic Energy Agency  have now joined forced to prevent the further spread of the cactus moth towards the cactus rich areas of southern USA and Mexico, and this includes monitoring the spread, an awareness campaign, training border and phytosanitary personnel and investigating new control methods. These include screening for new effective insecticides in South Africa, new detection methods using pheromone baited traps and designing a SIT (Sterile Insect Technique) programme.  The purpose is to create an insect-free barrier near the leading edge of its spread at the Florida/Alabama border. South Africa is not only playing a key role in preventing the further spread of  C. cactorum, but will eventually also benefit from this programme by taking advantage of new control methods that are to emerge.