Aerial and ground surveys to detect and evaluate forest insect and disease conditions in North Dakota were made during June 1977 by personnel from the U.S. Forest Service, Forest Insect and Disease Management staff and the Rocky Mountain Forest and Range Experiment Station. A forest tent caterpillar outbreak in the...
An active infestation of ash borer, Podosesia syringae (Harris) was detected in green ash, Fraxinus pennsylvanica Marsh, surrounding the Bowman-Haley Reservoir in 1973. A survey in 1974 showed that 40.4 percent of 690 trees examined contained active ash borer attacks. Forty-three out of 140 windbreaks were sampled and each one...
Green ash windbreaks in North Dakota were surveyed in 1972 and 1976 to determine the incidence of attacks by the carpenterworm, ash borer, and other stem-infesting wood borers. Windbreaks were stratified by age and geographic region. In 1976, about 3.1 percent of the green ash trees in North Dakota had...
1. Defoliation by cankerworms in 1979 was significantly less in 1978 treated shelterbelts than in untreated shelterbelts. 2. Most shelterbelts treated in 1978 retained enough foliage by late June 1979 so that adjacent crops were protected from wind. 3. Aerially applied Bt at a rate of 1/2 lb./acre provided shelterbelt...
The forest tent caterpillar, Malacosoma disstria Hbn., began defoliating trembling aspen stands, Populus tremuloides Michx., in 1976 in the Turtle Mountains of North Dakota. Heavy defoliation was scattered through about 150,000 acres in 1978. Pupal mortality from parasites and disease was almost 100 percent in cocoons on understory shrubs and...