European larch canker disease, caused by a fungus, Lachnellula (Dasyscypha) willkommii, was first reported in North America in 1927 (Spaulding and Siggers, 1927). The disease was effectively eradicated from Massachusetts by 1965 (Tegethoff, 1965), but a new infestation was found in Canada in 1980 (Magasi and Pond, 1982). Subsequently, infestations were observed in the coastal areas of eastern Maine (Miller-Weeks and Stark, 1983). In those areas where the disease is present, the canker has infested and damaged 50 to 100 percent of the larch in plantations or young managed stands (USDA Forest Service 1991). The severe impact of the canker on larch in parts of Europe and its potential impact on North American species has prompted Environment Canada, the USDA Forest Service, and Maine Forest Service to issue public-information flyers urging extreme caution in transporting cuttings and seedlings (USDA Forest Service, 1991).
USFS scientists and managers developed a conservation priority-setting framework for forest tree species at risk from pest & pathogens and other threats. The Project CAPTURE (Conservation Assessment and Prioritization of Forest Trees Under Risk of Extirpation) uses FIA data and expert opinion to group tree species under threat by non-native pests into vulnerability classes and specify appropriate management and conservation strategies. The scientists prioritized 419 tree species native to the North American continent. The analysis identified 15 taxonomic groups requiring the most immediate conservation intervention because of the tree species’ exposure to an extrinsic threat, their sensitivity to the threat, and their ability to adapt to it. Each of these 15 most vulnerable species, and several additional species, should be the focus of both a comprehensive gene conservation program and a genetic resistance screening and development effort. European larch canker is not known to be a threat to any of these 15 most vulnerable species.
Sources
Magasi, L.P. and S.E. Pond. 1982. European larch canker: A new disease in Canada and a new North American host record. Plant Dis. 66: 339.
Miller-Weeks, M. and D. Stark. 1983. European larch canker in Maine. Plant Dis. 67: 448.
Potter, K.M., Escanferla, M.E., Jetton, R.M., Man, G., Crane, B.S., Prioritizing the conservation needs of US tree spp: Evaluating vulnerability to forest insect and disease threats, Global Ecology and Conservation (2019), doi: https://doi.org/10.1016/
Spaulding, P. and P.V. Siggers. 1927. The European larch canker in America. Science 66: 480-481.
Tegethoff, A.C. 1965. Resurvey for European larch canker in Essex County, Massachusetts, 1965. Plant Dis. Rep. 49: 834
United States Department of Agriculture, Forest Service. 1991. Pest Risk Assessment of the Importation of Larch from Siberia and the Soviet Far East, Miscellaneous Publication No. 1495, September, 1991.