Exotic stressors such as emerald ash borer are an increasing concern to many communities across North America. One means of assessing the hazard these stressors may represent to a community’s publicly managed trees is through an inventory of their street trees. The South Dakota Division of Resource Conservation and Forestry conducted street tree inventories in selected communities across the state and, from these data, have placed communities into stability categories based on the percentage of full stocking that each genera represents within the street tree population. The majority of surveyed communities are in the low stability category as a result of the dominance of green ash in their street tree populations.

About 50% of 1,057 green ash (Fraxinus pennsylvanica) systematically sampled in the Great Plains and Rocky Mountain regions had substantial dieback (>10% of crown branches with dieback), and the average growth ring width during the last 20 years was 2.9 mm. The overall condition of the population was rated fair. Ash yellows phytoplasmas were identified at 102 of 106 sites throughout six U.S. states (North Dakota, South Dakota, Wyoming, Nebraska, Colorado, Kansas) and three Canadian provinces (Alberta, Saskatchewan, Manitoba). These phytoplasmas had not previously been known in Alberta, Saskatchewan, Manitoba, Wyoming, Colorado, or Kansas. Incidence of phytoplasmal detection ranged from 16% in Wyoming to 71% in South Dakota. Incidence varied in the range 41 to 67% across site types and crown dieback classes. Incidence was highest in rural plantings, in trees with the most crown dieback, and in larger diameter trees. No significant relationships were detected between presence of ash yellows phytoplasmas and radial growth rates of trees.

Many arborists provide cover sprays as part of their tree service. These sprays are applied without regard to tree condition or timed to fit the susceptible stage of any insect. While arborists are aware of the benefits of incorporating integrated pest management (IPM) into their practices, the public has been reluctant to purchase such a service. This is unfortunate since many excellent IPM programs have been developed over the past decade. To examine this reluctance, an analysis of the public perception of IPM was conducted using single-family residences in Mankato, Minnesota. The survey explored three separate areas: the homeowners' gardening experience, their attitude towards the IPM philosophy and what IPM tactics a homeowner would purchase as part of a tree and shrub service. The results of this survey and how they might be used to increase the use of IPM are discussed.

European white birch (Betula pendula) was the species most affected by birch dieback. Grey birch (B. populifolia) was occasionally affected. Paper birches (fi. papyrifera) showing symptoms of decline and dieback were rare. European white birches in good health rarely contained larvae of the bronze birch borer, Agrilus anxius. Trees in early stages of decline sustained borer larvae evenly distributed throughout the bole and main stem with lower numbers in the branches near the junction with the main stem. Trees exhibiting dieback symptoms contained high populations of borer larvae evenly distributed throughout the living cambium in the bole, main stem and live branches near the junction with the main stem, adult bronze birch borer beetles emerged only from areas where the cambium had died during the winter and early spring. Emergence did not occur from healthy trees or trees displaying early decline symptoms. Trees died back from branches in the crown; thus, adult beetles emerged in low numbers from branches of trees exhibiting dieback. The largest concentrations of adult beetles emerged from the boles and main stems of trees exhibiting advanced dieback symptoms.

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