Classical biological control of Old World climbing fern, Lygodium microphyllum

Old World climbing fern, Lygodium microphyllum (Cav.) R. Br., is one of the worst environmental weeds of southern Florida. The weed climbs over other plants, including tall trees, forming walls of vegetation. It also forms thick mats on the ground that smother native plants. The native range L. microphyllum includes the Old World from Africa to India, Southeast Asia, Australia, and some Pacific Islands. In the invaded range, Old World climbing fern invades much of the southern peninsula of Florida where cost-effective, sustainable control methods are needed. Climate modeling analysis was performed to predict the potential of this tropical species to establish in temperate environments. A series of no-choice tests was conducted on 68 plant species from 45 genera, 33 plant families, and 18 orders. The results indicate that Callopistria exotica and Lygomusotima stria are highly specific to the target weed, L. microphyllum and another congener that is also an exotic invasive, Lygodium japonicum. Climate modeling analysis indicates that these species pose little risk to more temperature non-target species. Both species are highly specific their release and redistribution will assist managers of natural areas control the invasive weed, L. microphyllum and L. japonicum