David Owens, Extension Entomologist, owensd@udel.edu
Cole Crops
Continue scouting cole crops. With the hot weather, be prepared to deal with both harlequin bug and diamondback moth. Diamondback moths have been present in larger numbers recently, while we still have not seen a cabbage looper in plots at Carvel REC.
Watermelon
Continue to scout for cucumber beetles and rind feeding lepidopteran worms on late melons.
Sweet Corn
Scout any whorl stage sweet corn for fall armyworm. New Jersey continues to report above threshold FAW populations, and we have been seeing them in various other crops. Thresholds are 15% early whorl infestation, 30% mid whorl, and 15% infestation at tassel push. While Besiege, Elevest, and Vantacor are labeled, using them for fall armyworm will use one of the chlorantraniliprole applications which in my opinion, are more important to save for the silking stages.
We are having a sweet corn oriented meeting at the Carvel REC on Tuesday, September 13 at 4:45. Attendees will have a chance to look at plots as well as hear updates on sweet corn management. With the hotter weather coming in and elevated moth counts, it may be best to tighten spray intervals. Just be sure to scout for aphid population increases.
Earworm counts from Thursday are as follows:
| Trap Location | BLT – CEW | Pheromone CEW |
| 3 nights total catch | ||
| Dover | 4 | 137 |
| Harrington | 1 | 46 |
| Milford | 12 | 124 |
| Rising Sun | 18 | 151 |
| Wyoming | 2 | 59 |
| Bridgeville | 3 | 53 |
| Concord | 11 | 66 |
| Georgetown | 1 | 98 |
| Greenwood | 2 | 47 |
| Laurel | 14 | 94 |
| Seaford | 3 | — |
| Lewes | — | 296 |
Spinach
Scout spinach as soon as its up for beet armyworm. New Jersey is reporting heavy beet armyworm activity in some locales. Remember, pyrethroids will not control beet armyworm. Other options include the diamide class, Avuant, Intrepid, Bt, Proclaim, and Radiant or Entrust.