Paul Pratt, prattp@saa.ars.usda.gov, USDA-ARS, Invasive Plant Research Lab, 3225 College Ave, Fort Lauderdale, FL
Invasion of south Florida wetlands by the Australian paperbark tree (“melaleuca”), Melaleuca quinquenervia has caused adverse economic and environmental impacts. Its biological attributes along with favorable ambient biophysical conditions combine to make M. quinquenervia highly invasive in wetland communities. Management requires an integrated strategy that deploys multiple biological control agents to forestall reinvasion and to supplement other control methods thereby lessening recruitment and regeneration after removal of existing trees. This program began during 1997 with the release of an Australian weevil (Oxyops vitiosa). A second Australian insect, the melaleuca psyllid (Boreioglycaspis melaleucae) first introduced during 2002, has widely established. Only 40% of seedlings survived psyllid inoculation treatments compared to 95% survival in controls in a field study. The resultant defoliation also reduced growth of the surviving seedlings. Non-target plant species postulated to be at risk were unaffected when interspersed with psyllid-infested melaleuca trees in a common garden study. Evaluations are ongoing, but B. melaleucae is clearly reducing seedling recruitment and stump regrowth and is not affecting other plant species. Manifestation of impacts on saplings and mature trees will require more time but preliminary indications suggest that the psyllid will be an effective biological control agent.
Species 1: Hemiptera Psyllidae
Boreioglycaspis melaleuca (melaleuca psyllid)