Exploratory surveys in Australia and Asia for natural enemies of Old World climbing fern, Lygodium microphyllum: Lygodiaceae

Abstract

Lygodium microphyllum, Old World climbing fern, is native to the wet tropics and subtropics of the Old World and an invasive weed in southern Florida. Exploration for natural enemies of this weed was conducted between 1997 and 2002 in Australia, China, India, Indonesia, Japan, Malaysia, New Caledonia, Singapore, Taiwan, Thailand, and Vietnam. Two species of mites and 20 insect species were collected. The eriophyid mite, Floracarus perrepae Knihinicki and Boczek, was the most widely distributed and appeared to cause significant damage to the plant over time. Several unique geographical genotypes of F. perrepae were identified. Other promising candidates for further research are the musotimine pyralid species, Neomusotima conspurcatalis Warren, Cataclysta camptozonale Hampson, Cataclysta sp. 2, and Musotima sp., all leaf-feeders, as well as the stem-borer Ambia sp. All of the herbivores collected, except the eriophyid, typically occurred at low field densities. The pyralid species may reach high densities and cause great damage in Florida in the absence of their co-evolved natural enemies. The mite F. perrepae shows the greatest potential for biological control based on field surveys and initial laboratory observations; however, future studies must identify mite genotypes that are best adapted to the invasive Florida form of the fern. Published by Elsevier Science (USA).