David Owens, Extension Entomologist, owensd@udel.edu
Sweet Corn
Trap counts have decreased considerably, with many sites now catching a number indicative of a 4-day spray schedule. Please keep in mind that we do not move most of our traps. A handful are near silking sweet corn, but the majority are not. Trap counts are as follows:
| Location | Blacklight Trap | Pheromone Trap |
| Dover | 0 | 4 |
| Harrington | 0 | 2 |
| Milford | 1 | 4 |
| Rising Sun | 1 | 5 |
| Wyoming | — | 20 |
| Bridgeville | 1 | 7 |
| Concord | 2 | 66 |
| Georgetown | — | — |
| Greenwood | 0 | 8 |
| Laurel | 4 | 7 |
| Milton | — | 3 |
Cole Crops
Many of our brassica crops are cupping or beginning to initiate curds. The threshold decreases to 15% infested plants at this stage and 5% from curd development until harvest. In Georgetown, all of the brassica worms are present, including the less common cole pests corn earworm, beet armyworm, and fall armyworm. Together with diamondback moth, these worms are resistant to pyrethroids. Rotate among your modes of action. Make sure that you get good coverage with high water volumes. If you can, nozzles directing the spray over the top of the head and to the sides of the plants would be ideal. Use of spreaders can also help but be careful with stickers! Diamides and stickers do not play well together. We still have a lot of natural enemy activity in the crop, keep using the more IPM-friendly materials. Aphid pressure has also been high this fall. Aphids that have swelled and turned into a round, straw colored ball have been attacked by parasitoid wasps.
Tomatoes
Continue to monitor for signs of worm activity in the crop and treat accordingly. Look for frass, fresh on plants. In Georgetown, we have both cabbage looper and corn earworm damaging late tomatoes. If worm activity is noted, use one of the recommended worm materials in the Commercial Vegetable Production Recommendations guide: https://www.udel.edu/academics/colleges/canr/cooperative-extension/sustainable-production/commercial-crops/vegetable-crops/midatlantic-vegetable-recommendations/.