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WoodwaspnAmylosterelun complex 



The woodwasp Sirex noctilio and associated fungus Amylostmum areolatum can cause 

 tree mortality. The wasp is native to Eurasia and North Africa, but it has become 

 established in New Zealand, Australia, and southern South America. Sirex noctilio fe- 

 males fly (100-mile range) to locate physiologically stressed trees to deposit their 

 eggs. The wasp primarily infests pine species, but has been recorded as infesting fir 

 and spruce. During oviposition, the Amylosiereum lungus with a toxic mucus are inject- 

 ed into the tree (USDA Forest Service 1992). In Australia and South America, this 

 complex causes significant tree mortality. New Zealand controls the pest by biological 

 control agents and improved stand management (USDA Forest Service 1992). 



While the assessment ranks the risk of shipping infested Pintis radiata logs as low, 

 there is a possibility of larval survival deep within the logs. If importation were to 

 occur, the assessment considers that S. noctilio would probably become established 

 and spread throughout the western United States. The authors estimate the econom- 

 ic costs resulting from establishment of the S. noctilio-A. areolatum complex at between 

 $24 and $131 million in timber revenues alone (USDA Forest Service 1992). 



Lepiographium truncatum 



The pathogen Lepiographium truncatum is found on two North American endemic spe- 

 cies, Monterey pine and eastern white pine, in New Zealand. The pathogen is consid- 

 ered by some to be the same as L lundbergii, which attacks eastern white and loblolly 

 (,Pinus taeda) pines (USDA Forest Service 1992). The vector(s) for the fungi are not 

 known with certainty, but bark beedes are suspected (USDA Forest Service 1992). 



No effective method of conu-olling this fungus in logs is available. The assessment 

 team considers that debarking would reduce the risk of transporting vectors from 

 New Zealand, but North American beedes may be able to carry die fungus. Suitable 

 u-ee hosts are found near the Pacific ports where imports are proposed (USDA Forest 

 Service 1992) (as well as near Gulf Coast ports). Increased tree mortality in commer- 

 cial forests, ornamental plantings, and Christmas tree plantations would be possible, 

 with the greatest impact on native stands of Monterey pine (USDA Forest Service 

 1992). 



Two pests already present in Nortli America might be rcinu-oduccd from New Zealand. 

 Diplodia shoot blight (Dtplodta ptnea = Sphaeropm sapinea) and the previously dis- 

 cussed Melampsora poplar rust arc pests in New Zealand forests. Importation of New 

 Zealand logs without proper quarantine protocols presents the possibility of introduc- 

 ing more virulent strains or spreading infestation of these two pathogens to new 

 areas. 



New Zealand has had the reputation of applying stringent pest-exclusion programs 

 for several decades Since adoption of The Forests Act in 1949, the owner has had to 

 pay the cost of inspections, searches, seizures, required treatment or destruction, etc. 

 when importing raw wood. Experts considered that such precautions had helped 

 limit establishment of new wood and bark boring insects to an average of one per 

 year, despite increasing trade. They admitted, howevt., that "no method is available 

 to estimate accurately how effective quarantine has been in preventing the establish- 

 ment of forest pests" and that "[t]he effecuveness of New Zealand's quarantine pro- 

 cedures against fungal and other pathogens is difficult to evaluate because intercep- 

 tions cannot be related to establishments" (Anonymous 1982). 



Governmental surveys, carried out in the late 1970s and 1980s, focussed particular 



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