East Lansing, Michigan: emerald ash borer larval density in green ash street trees and canopy thinning ratings of the same trees for one to three years after a single trunk injection of emamectin benzoate at a rate of 0.4 g ai/inch dbh on September 27, 2005, or at 0.2 or 0.1 ai/2.54 cm dbh on May 21, 2007. Data are means ± SD. Each treatment has 10 replications unless indicated otherwise under the mean ± SD by (n).
| Treatment | Treatment Dates | 2006 dbh (cm) | 2006 canopy Thinning (%) | 2007 canopy thinning | 2007 Larvae per m2 | 2008 canopy Thinning (%) | 2008 larvae per m2 | 2009 canopy thinning (%) |
|---|---|---|---|---|---|---|---|---|
| Emamectin trunk injection 0.4 g ai/inch dbh | Sept. 2005 | 29.9 ± 11.4 | 7.3 ± 8.9 | 12.8 ± 14.8 | 0 ± 0 A | 19.3 ± 17.9A | 0 ± 0 A | 13.8 ± 14 A |
| Emamectin trunk injection 0.2 g ai/inch dbh | May 2007 | 29.2 ± 4.1 | 11.8 ± 1.6 | 17.3 ± 13.5 (9) | 0 ± 0 A (9) | 12.8 ± 8.8 A (9) | 0 ± 0 A (9) | 13.1 ± 13.3 A (9) |
| Emamectin trunk injection 0.1 g ai/inch dbh | May 2007 | 38.2 ± 7.3 | 17.0 ± 10.5 | 11.4 ± 15.9 | 0 ± 0 A | 29.8 ± 29.4 A | 0 ± 0 A (6) | 10.4 ± 9.1 A (7) |
| Control | - | 28.7 ± 10.6 | 16.0 ± 21.0 | 28.5 ± 27.9 | 6.9 ± 9.4 B | 51.3 ± 30.2 B | 28.7 ± 21.5 B | 58.1 ± 33.2 B |