Twenty year costs for annual aphid honeydew management for 400 University Avenue tuliptrees in Berkeley, California.*
| Method | Annual cost per tree | Total 20 year cost for 400 tuliptrees |
|---|---|---|
| Sidewalk washing (weekly Jun-Sep.) | $38.40 | $307,200 |
| Canopy soap sprays (3 times/yr.) | 24.00 | 192,000 |
| Injection (once/yr.) | 9.00 | 72,000 |
| Chemical sprays (2 times/yr.) | 12.00 | 96,000 |
↵* Values are in 1 984 dollars.