Biological Control 53, 1-8 (2010)

Biological control is a widely used method of controlling invasive species. The melaleuca tree (Melaleuca quinquenervia), an Australian native currently populating the Florida Everglades, has had devastating effects on the ecosystem. Several biological control agents have been used in an attempt to reduce melaleuca populations.

Min Rayamajhi and his colleagues at the USDA investigated the effectiveness of three biological control agents, herbivorous insects Oxyops vitiosa (weevil) and Boreioglycaspis melaleucae (psyllid) as well as rust fungus Puccinia psidii individually and together. 120 trees were felled, harvested and measured for damage, height, branching, mortality, and biomass for each of the groups. The team found that when used in conjunction, these three control agents caused more damage to the melaleuca than when used separately. Because of their interspecies competition, the insects and fungi each feed on different parts of the tree, resulting in more widespread control. The authors concluded that these species have great potential to suppress melaleuca growth in the Everglades.