David Owens, Extension Entomologist, owensd@udel.edu
Cucurbits
Watermelons are fairly quiet right now. Continue scouting for spider mites. Recent hot dry weather will stimulate mite reproduction, and we are seeing some increase, though not at threshold level, in fields treated earlier this year. Also be sure to note the presence of any caterpillars that could feed on developing fruit rinds. Cucumber beetle may begin coming out of the soil again this week coming.
Legumes
Be on the lookout for potato leafhopper, especially on young plants. Thresholds are 5 per sweep. Also be scouting for tarnished plant bug and stink bug. The threshold for TPB is 15 per 50 sweeps while for stink bugs it is 7 per 50 sweeps. We have had quite a bit of stink bug movement in our blacklights, and tarnished plant bug has been active this season.
Sweet Corn
Moth pressure continues declining statewide. Monday and Thursday trap data is uploaded to our website: https://agdev.anr.udel.edu/trap/trap.php. For reference, action thresholds based off of blacklight and pheromone trap can be found here: https://www.udel.edu/academics/colleges/canr/cooperative-extension/sustainable-production/pest-management/insect-trapping/silk-stage-sweet-corn/. Thursday’s trap capture is as follows:
| Trap Location | BLT – CEW | Pheromone CEW |
| 3 nights total catch | ||
| Dover | 0 | 34 |
| Harrington | 0 | 51 |
| Milford | 0 | 24 |
| Rising Sun | 0 | 58 |
| Wyoming | 0 | 5 |
| Bridgeville | 1 | 17 |
| Concord | 1 | 48 |
| Georgetown | 0 | 5 |
| Greenwood | 1 | |
| Laurel | 1 | 27 |
| Seaford | 0 | 12 |
| Lewes | 0 | 3 |
| Harbeson | 0 | |
| Millsboro | ||