RECENTLY INTRODUCED PESTS 



Three new exotic forest pests have been discovered in North 

 America during the past 2 years. Asian gypsy moth, a serious pest 

 of conifers and hardwoods in Asia, was discovered in Oregon, 

 Washington, and British Columbia in 1991. This gypsy moth laid 

 its eggs on the superstructure of cargo vessels while these vessels 

 were in Russian ports. When the vessels reached North America 

 the eggs hatched and larvae were carried by the wind into nearby 

 forests. The successful eradication and survey effort cost the 

 Federal and State governments $19 million in 1992. Additional 

 funds were spent by public agencies in Canada to eradicate the 

 pest there. 



The common European pine shoot beetle, an important pest of trees 

 in Europe and Asia, was discovered in Ohio in 1992 and subse- 

 quently in Indiana, Illinois, Michigan, New York, Ohio, and Penn- 

 sylvania. A Federal quarantine was placed on infested counties to 

 regulate movement of logs, lumber, nursery stock, and Christmas 

 trees into other areas of the United States. The Eurasian poplar 

 leaf rust was discovered in California, Oregon, and Washington in 

 1992. 



RISK OF NEW INTRODUCTIONS 



Many forest pests that might adversely affect forests in this coun- 

 try are known to occur in other parts of the world and have not 

 been introduced into North America. With increasing interna- 

 tional trade, including the possible importation of logs as well as 

 wood products, the risk of additional introductions will increase. 

 Keeping these pests out is critical to protecting forest ecosystems 

 in North America. 



Concerns about the potential for new introductions have greatly 

 increased since 1990, when commercial interests proposed 

 importing larch logs from Siberia. In 1991, at the request of the 

 USDA Animal and Plant Health Inspecdon Service (APHIS), 

 the Forest Service completed a pest risk assessment of importing 

 Russian larch logs (USDA Forest Ser\'ice 1991). The assessment 

 found that any one of several forest pests in Russia could cause 

 serious damage if introduced into the United States. Similar pro- 

 posals were later received for log importations from New Zealand 

 and Chile. The pest risk assessment completed for New Zealand 

 logs also found pests of concern if Monterey pine logs were to 

 be imported without appropriate quarantine measures (USDA 

 Forest Service 1992). A pest risk assessment is underway for log 

 importations from Chile. 



Healthy Forests for America 's Future — A Strategic Plan 1 9 



