CACTOBLASTIS CACTORUM (LEPIDOPTERA: PYRALIDAE) IN NORTH AMERICA: A WORKSHOP OF ASSESSMENT AND PLANNING

Abstract

The cactus moth, Cactoblastis cactorum Berg (Lepidoptera: Pyralidae), has been an important biological control agent of introduced and weedy prickly pear cacti (Opuntia spp., Cactaceae) in many parts of the world. Cactoblastis, a native of Argentina, was introduced into the Caribbean in 1957 to control weedy, but native species of prickly pear infesting rangeland. It has spread through the Caribbean and in 1989 was first found in Florida. It has now spread as far north as coastal Georgia. There is a continuous distribution of acceptable host species of Opuntia from southern Florida across the southern United States to the Pacific Coast. Mexico is a center of endemism and has many species of Opuntia. Prickly pear cacti constitute a highly important and uniquely desert-adapted subsistence food and cash crop in Mexico. Prickly pears have other valuable uses, such as in the production of cochineal dye and in desert landscaping. Because Cactoblastis readily attacks many novel hosts within Opuntia, it will likely have serious impacts on the ecology of desert environments and on the agricultural and horticultural uses of prickly pears. Further, if Cactoblastis does result in significant damage, it is likely to serve as another source of criticism of classical biological control. Cactoblastis cactorum in North America, A Workshop of Assessment and Planning, was held in Tampa, Florida in September 2000. Major subject areas covered include the biology and economic importance of Opuntia, the biology, biological control history, and current status of Cactoblastis, and potential methods of controlling Cactoblastis in North America. This paper summarizes findings of the workshop and provides an introduction to the workshop proceedings.