Dutch elm disease in western Oregon, 1 986 

 to 1 995. The 1 986 figures are from Eugene 

 and Portland. The 1987 to 1995 figures are 

 removals from Portland, plus a few trees from 

 private home owners outside of Portland. 



Source: Oregon Department of Agriculture. 



Dutch elm disease is increasing in 

 Oregon and Washington — American elm is an 

 important component of the mature urban for- 

 est environment, both east and west of the 

 Cascades in the Pacific Northwest. Dutch elm 

 disease is an introduced disease that has dev- 

 astated trees throughout the United States and 

 is of worldwide importance. This aggressive 

 disease is spread from tree to tree by elm bark 

 beetles, which cany disease spores, and also 

 when the fungus grows from roots of an in- 

 fected tree to roots of adjacent healthy trees. 



Dutch elm disease was first detected in Or- 

 egon in the Nyssa-Ontario area and in Wash- 

 ington in Walla Walla in the 1970s. Despite 

 control efforts, the disease has since spread 

 to other locations throughout the two states. 



The key to reducing spread and losses from 

 this disease is prompt removal and disposal 

 of infected trees, but many cities and towns 

 have no such programs. In Oregon, many 

 towns remove infected trees and dispose of the 

 chipped wood at a solid waste site. The city of 

 Portland injects elm trees with fungicides as a 

 protectant against the disease. 



Gypsy moth — the vigil continues — The 



first European gypsy moths were discovered 

 in 1974 in Washington in the city of Renton 

 (near Seattle) and in 1979 in Oregon in Lake 

 Oswego (near Portland). Since then, gypsy 

 moth has been monitored annually by the Or- 

 egon and Washington Departments of Agricul- 

 ture. In 1995, more than 50,000 traps were 

 deployed in Oregon and Washington, mostly 

 west of the Cascades, where most population 

 centers and gypsy moth host material are lo- 

 cated. 



The 1995 gypsy moth monitoring in Oregon 

 and Washington had the following results: 



Oregon 



Washington 



The newest arrival is the Asian gypsy moth; 

 it is potentially more serious than the Euro- 

 pean gypsy moth because females can fly, and 

 they have an appetite for conifers. In the last 



The European gypsy moth larva, pictured here, 

 feeds mainly on hardwood foliage. Its cousin, iJie 

 Asian gypsy moth, feeds on conifers and so 

 presents a greater threat to the Pacific 

 Northwest 



Urban— 62 



