Condition of Green Ash, Incidence of Ash Yellows Phytoplasmas, and Their Association in the Great Plains and Rocky Mountain Regions of North America.

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.

Identification and field testing of female-produced sex pheromone components of the spring cankerworm,Paleacrita vernata Peck (Lepidoptera: Geometridae).

Two sex pheromone components, 3(Z),6(Z),9(Z)-nonadecatriene (3Z,6Z,9Z-19 ∶ H), and 3(Z),6(Z),9(Z)-eicosatriene (3Z,6Z,9Z-20∶ H), have been positively identified, and a third component, 6(Z),9(Z)-nonadecadiene (6(Z),9(Z)-19 ∶ H) has been tentatively identified from abdominal tip extracts of female spring cankerworm moths,Paleacrita vernata Peck (Lepidoptera∶ Geometridae). The pheromone components were identified by a combination of gas chromatography, electroantennography, mass spectrometry, chemical tests, comparison with standards, and field testing. Only 3Z,6Z,9Z-20 ∶ H exhibited significant attractant activity when tested alone, and it was potentiated by the other two components. The attractive blend was an 8∶2∶1 ratio of 3Z,6Z,9Z-20∶H/3Z,6Z,9Z-19∶H/6Z,9Z-19∶H. However, the two-component blend of 3Z,6Z,9Z-20 ∶ H and 6Z,9Z-19 ∶ H (8∶1 ratio) was as attractive as the three-component blend in further field tests. A series of related compounds, the diene monoepoxides available from epoxidation of C19 and C20 3Z,6Z,9Z-trienes, some of which have been found in the pheromone blends of other moth species, were tested as behavioral antagonists. The attraction of male moths to synthetic lures was suppressed by the addition of 6Z,9Z-cis-3,4-epoxy-nonadecadiene to the lures. Additional experiments were performed to determine the effects of lure dosage, trap height, and trap design on the numbers of male moths captured.