In South America, the rate of afforestation with exotic pines has dramatically increased during the last two decades. The countries of South America are dependent on plantations of fast-growing trees to help meet their national needs for lumber, pulpwood, fuelwood, and other wood products. Also, these plantations alleviate the pressure on some naturally occurring species in areas such as the Amazon Basin, Atlantic Forest, and Auraucaria Forest. There are presently 5.0 million hectares of forest plaiitations in Brazil, of which 2.0 million hectares consist of various species of pines. Pines in South America were relatively pest-free; however, in the early 1990s, several species of insects and fungi were accidentally introduced into the continent. These pests have caused wide¬ spread, serious damage. Several pest species now threaten the future viability of pine, as well as tree biodiversity as a component of South American forestry programs. Sirex noctilio F. (Hymenoptera: Siricidae), is native to southern Europe, the Near East, and north Africa, where it is a secondary invader in the boles of weakened and dying pines. It is not considered a pest in its native habitat. This horntail is associated with a fungus, Amylostereian areolatiim, which is toxic to certain pines. By the mid 1980s, S. noctilio was causing extensive mortality In New Zealand, Tasmania, and Australia. Sirex noctilio was first reported in South America (in Uruguay in 1980). In 1988 it was found in the southern part of Brazil. It has caused widespread losses, and, in some local cases, has resulted in over sixty-percent mortality in pine plantations in Brazil and neighboring countries. In Brazil, the insect presently occurs in the southern states of Rio Grande do Sul, Santa Catarina, and Paraná, and covers an area of approximately 200,000 hectares of pine plantations. This region contains approximately sixty percent of the country's pine plantations. Current annual losses attributed to S. noctilio in this region are estimated at US$ 5 million. There is a tremendous potential for further spread of this pest in South America, especially into Chile, which has in excess of 1.3 million hectares of Monterey pine (Finns radiata D. Don.) plantations. Additionally, countries such as the United States are potentially threatened by S. noctilio as interna¬ tional trade increases.