David Owens, Extension Entomologist, owensd@udel.edu and Bill Cissel, Extension Agent – Integrated Pest Management; bcissel@udel.edu
Watermelon
by David Owens
Two spotted spider mites continue to be an issue in fields. Now that the first melons are being harvested, there are occasional reports of rind-feeding worms of various species. There are numerous products that should provide good efficacy, but you will need high water rates because rind feeding worms are likely to be in sheltered locations. Pay attention to pre-harvest intervals and bee toxicity, apply later in the day to avoid direct contact with foragers. Cucumber beetles are also active.
Sweet Corn
Bill Cissel and David Owens
Trap counts are much higher this week in several sites, and counts below are higher than they were on Monday. As expected, earworm activity is beginning to pick up and will probably continue to climb through August. Be sure to scout pretasseling corn as well for whorl feeding earworm and potential fall armyworm. Although we are not trapping specifically for fall armyworm, they often show up in late July, and Virginia is currently capturing low numbers of them.
Sweet corn trapping data is updated by Tuesday and Friday mornings and can be accessed here: http://agdev.anr.udel.edu/trap/trap.php. Do not rely on a single trap site to make spray decisions; take a look at nearby traps and note the general statewide trend. You may have more corn earworms in tassel-push/ early silk sweet corn than what some of these traps may indicate. Trap catches from Monday, Tuesday, and Wednesday night are as follows:
| Trap Location | BLT – CEW | Pheromone CEW |
| 3 nights total catch | ||
| Dover | 1 | 74 |
| Harrington | 0 | 1 |
| Milford | 0 | 4 |
| Rising Sun | 4 | 43 |
| Wyoming | 0 | 27 |
| Bridgeville | 0 | 12 |
| Concord | 0 | 23 |
| Georgetown | 0 | 3 |
| Greenwood | 0 | 0 |
| Laurel | 0 | 36 |
| Seaford | 1 | 51 |