|Mariana, Manteca Acosta|
Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2012
Publication Date: 12/1/2012
Citation: Varone, L., Mariana, M., Logarzo, G.A., Briano, J., Hight, S.D., Carpenter, J.E. 2012. Performance of cactoblastis cactorum (Berg)(Lepidoptera:Pyralidae) on South and North American Opuntia species occurring in Argentina. Florida Entomologist. 95(4):1163-1173. Interpretive Summary: The cactus moth, Cactoblastis cactorum, is native to South America and feeds on many species of Opuntia cacti. Since the 1920s, the cactus moth has been successfully used for the biological control of invasive Opuntia cacti in Australia and Africa, where no native cacti occur. Its release in the Caribbean to control native Opuntia resulted in its accidental arrival in the U.S. in 1989 and to Mexico in 2006. In the U.S., the cactus moth spread to the west reaching Louisiana in May 2009, becoming a threat to wild and cultivated Opuntia spp. in the southwestern US and Mexico. This study was aimed at better understanding the biology and ecology of C. cactorum in Argentina, the native range, so as to contribute to the development of control strategies. We tested the cactus moth development success on eight different South and North American Opuntia species. We found that the cactus moth developed better on the North American cactus pear (O. ficus.indica) than any other Opuntia, indepently of the origin of the cactus moth populations. The better performance of the cactus moth on cultivated O. ficus-indica could have severe consequences for the cactus pear industry in Mexico and the U.S., which is based on cultivars of this species. In contrast, the South American Opuntia species seemed to be more resistant to the cactus moth feeding on it and provided inferior quality food.
Technical Abstract: The cactus moth, Cactoblastis cactorum, is native to South America. Since the insects’ unintentional arrival to the US in 1989 and to Mexican islands in 2006, it has become a serious threat to the diversity of Opuntia species in North America and to the wild and cultivated species of Opuntia. The native ecological host range of C. cactorum has not been ascertained; preliminary field explorations revealed differences in feeding damage among the host species. This study was aimed at better understanding the biology and ecology of C. cactorum in Argentina by evaluating, under laboratory conditions, the insects’ performance (survivorship, development time, fecundity) in eight South and North American Opuntia spp. occurring in Argentina. As the insects for the experiments were originally collected on O. ficus-indica, a reciprocal cross experiment was also conducted to analyze a potential host plant-mediated local adaptation effect. In general, C. cactorum performed better on the North American O. ficus-indica and O. robusta, and the South American O. arechavaletae. Some evidence for local adaptation to a South American and poor quality host was detected. High performance of the cactus moth on cultivated O. ficus-indica could have severe consequences for the cactus pear industry in North America.