. Forest insect and disease conditions in the United States 1979. Insect pests United States. mental planting near Cloquet, Minn., were found to be heavily infected with scleroderris cankers. The source of inoculum for these infections by the North American strain of the fungus is not known. In Vermont, 70 plantations (600 acres) were infected by the European strain, while in New York the fungus was found on about 50,000 acres. Quarantines of affected counties in these two States remained in effect. Only one planta- tion in New Hampshire (European strain) and one in Maine (North American strai
. Forest insect and disease conditions in the United States 1979. Insect pests United States. mental planting near Cloquet, Minn., were found to be heavily infected with scleroderris cankers. The source of inoculum for these infections by the North American strain of the fungus is not known. In Vermont, 70 plantations (600 acres) were infected by the European strain, while in New York the fungus was found on about 50,000 acres. Quarantines of affected counties in these two States remained in effect. Only one planta- tion in New Hampshire (European strain) and one in Maine (North American strain) were infected. However, there are several planta- tions in Quebec, Canada, just north of the Maine, New Hampshire, and Vermont borders that were infected with the European strain. Beech bark disease results from the combined effects of a scale insect, Cryptococcus fagisuga Lind., and a fungus, Nectria coccinea Var. Faginata Loh., Wats. & Ay. The dis- ease is present throughout New Eng- land and New York, and in 1979 it was spreading west and south into Pennsylvania and New Jersey. A se- cond wave of the disease is killing beech regeneration in areas pre- viously infected. Diebacks and declines were ob- served this year in many States on several species of hardwoods. Ash dieback was reported in Indiana, Ohio, New York, and Vermont, while in southern Wisconsin many ashes experienced unexplained pre- mature leaf fall. Stress-induced dieback and mortality of oaks in Il- linois, Indiana, Iowa, Michigan, Minnesota, Missouri, and Wisconsin often were associated with drought, Armillaria root rot, and two-lined chestnut borers. In Indiana alone, an estimated 321,778 board feet of affected oaks were lost. Maple decline occurred in the western Up- per Peninsula of Michigan, northern Wisconsin, southern Minnesota, and the sugar bushes of Vermont. Dieback of paper birch in Minnesota and yellow birch in Vermont and the western Upper Peninsula of Michigan was prevalent this year. Damag
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