Biological Control of Forest Pests in Uruguay

Abstract

Commercial tree plantations cover around a million ha in Uruguay, mostly with stands of eucalypt and pine trees. Uruguayan forestry was free of serious insect pest until the end of the twentieth century. Beginning in the 1990s, both forestry area and international trade experienced an exponential growth, followed by an increase of invasive insect records. More than half of the pests currently affecting Eucalyptus entered the country after 1995. The use of pesticides is greatly restricted, provided around 90% of the plantations are under FSC and/or PEFC certification schemes. Hence, the Uruguayan forestry has relied mainly on silvicultural and biological control to suppress insect pest populations. Biological control for forest insect pests in Uruguay can be tracked back to 1941. Currently, biological control with entomophagous or entomopathogenic organisms has been, or is currently being, implemented for eight insect pests in plantations in Uruguay. More than five parasitoid wasps and a nematode have been released and installed in the field. There are also at least two cases of introduction of entomophagous organisms simultaneously with the pest. I discuss the future of biological control in Uruguay, focusing on the advantages it possesses and the challenges it faces under the current pest status.