The reported use of sprays by commercial arborists in 1982 to control insects or diseases, and the ranking of relative importance within each.
| Use frequency (no. arborists) | Relative importancea | |||
|---|---|---|---|---|
| Problem | First | Second | Third | |
| Diseases | ||||
| Anthracnose | 11 | 6 | 5 | 9 |
| Blights | 14 | 5 | 3 | 3 |
| Canker or dieback | 7 | 2 | 1 | 3 |
| Galls | 14 | 1 | 3 | 0 |
| Leaf spots | 19 | 2 | 5 | 4 |
| Powdery mildew | 14 | 2 | 2 | 4 |
| Rust | 13 | 4 | 11 | 5 |
| Scab | 11 | 14 | 5 | 6 |
| DED | 12 | 4 | 3 | 2 |
| Insects | ||||
| Aphids | 28 | 5 | 10 | 7 |
| Bagworms | 22 | 10 | 3 | 3 |
| Borers | 34 | 7 | 6 | 4 |
| Caterpillars | 35 | 5 | 4 | 4 |
| Elm bark beetles | 24 | 1 | 2 | 3 |
| Gallmakers | 20 | 0 | 1 | 0 |
| Leaf beetles | 26 | 0 | 1 | 2 |
| Leafminers | 32 | 1 | 1 | 0 |
| Leafhoppers | 24 | 1 | 2 | 1 |
| Mites | 31 | 4 | 4 | 8 |
| Moths (gypsy or tussock) | 16 | 1 | 0 | 0 |
| Plant bugs | 19 | 0 | 0 | 0 |
| Scale insects | 23 | 10 | 8 | 6 |
| Webworms | 29 | 1 | 2 | 6 |
↵a The number of arborists who rated this disease (or insect pest) as first, second, or third in importance in his area.