David Owens, Extension Entomologist, owensd@udel.edu
Tomatoes
Continue treating for worms. Soybean looper activity at Carvel is very high in tomato plots, which is unusual. Loopers are difficult to kill, with some of the most effective materials being Proclaim and Avaunt. Pyrethroids provide very little control.
Sweet Corn
Pheromone trap counts continue to slowly decrease. The pheromone trap network has been generously supported by DDA Specialty Crop Block Grant FB 22-04 and USDA NIFA SCRI 2023-51181-41157. We will continue monitoring pheromone traps for another couple of weeks.
| Location | Blacklight Trap | Pheromone Trap |
| Dover | 0 | 3 |
| Harrington | 0 | 9 |
| Milford | 4 | 3 |
| Rising Sun | 0 | 0 |
| Wyoming | 0 | 22 |
| Bridgeville | 1 | 7 |
| Concord | 7 | — |
| Georgetown | ||
| Greenwood | 1 | 3 |
| Laurel | 4 | 11 |
| Milton | 28 (7 days) |
Cole Crops
All cole crop worm pests are active. At Georgetown, cross striped worms, corn earworm, beet armyworm, and fall armyworm are active and are the most damaging or difficult to control. Imported cabbageworm is very active. Curiously, we have seen a few cabbage looper. Thresholds decrease during early cupping and early head formation stages.
Spinach and Lettuce
Continue scouting for beet armyworm and beet webworm. Pyrethroids alone are not recommended for either species. Scout also for aphids. Aphid populations tend to increase in early Fall before they seek overwintering sites. Natural enemies can also be problematic in leafy greens because the aphid mummies left behind by parasitoids are more easily seen by consumers and harder to wash off the leaves. There are many aphid materials with good to excellent efficacy, and a fair number of aphids recommended insecticides also control worms.