David Owens, Extension Entomologist, owensd@udel.edu
Cucurbits
Begin scouting for first generation striped cucumber beetles. It takes nearly 30 days for larvae to complete development, adults starting flying around the third-fourth week of May. Adults in this generation can feed on rinds. In recent trials and bioassays conducted on Delmarva, pyrethroids have been somewhat inconsistent in controlling them. Acetamiprid, cyclaniliprole and cyantraniliprole, and carbaryl demonstrated good efficacy. Carbaryl can flare mites. The diamides cyclaniliprole (Harvanta) and cyantraniliprole (Exirel, Minecto Pro) are excellent worm products.
Scout fruit for evidence of Lepidopteran rind feeding. Worm scars tend to be larger and smooth, whereas beetle scarring tends to be more uneven, resulting in a ‘dirty’ look.
Spider mite counts in melon fields we have been scouting are lower this week than last.
Sweet Corn
Scout for whorl stage fall armyworm infestations. Last week we captured a couple of fall armyworm in pheromone traps. This week, scattered whorl infestations were reported in southern New Jersey.
Corn earworm captures in pheromone traps continue to be fairly low. We captured on of our first European corn borer this week in Seaford. Trap captures are as follows:
| Trap Location | BLT – CEW | Pheromone CEW |
| 3 nights total catch | ||
| Dover | 0 | 15 |
| Harrington | 0 | 20 |
| Milford | 1 | 9 |
| Rising Sun | 1 | 28 |
| Wyoming | 0 | 4 |
| Bridgeville | 0 | 4 |
| Concord | 0 | 12 |
| Georgetown | 0 | 11 |
| Greenwood | 1 | 21 |
| Laurel | 0 | 17 |
| Seaford | 0 | — |
| Lewes | — | 19 (1 night) |