The Potential of Biological Control to Manage Old World Climbing Fern (Lygodium microphyllum), an Invasive Weed in Florida

Abstract

-Lygodium microphyllum is native to wet tropical and subtropical Africa, Asia, Australia, and the Pacific islands. The genus Lygodium is taxonomically isolated and has only one native species in North America. Specialized natural enemies of L. microphyllum are predicted to exist that can be safely employed to control the fern in Florida, where it is a severe problem. Lygodium microphyllum (Cav.) R. Br., or Old World climbing fern, is a serious weed in southern Florida, as described in the companion to this paper (Pemberton and Ferriter, 1998). In an attempt to reduce populations of this plant and to limit its spread, a biological control research effort is being initiated. The theory of biological control and the suitability of this approach to reduce and manage L. microphyllum are discussed. To help lay the groundwork for the biological control effort, the native range and taxonomic relations of the fern are defined. This information is used to plan and conduct surveys for natural enemies as well as research to define the potential host ranges of candidate biological control agents. The question of whether insects and other natural enemies can be expected to be associated with L. microphyllum is addressed.