Vegetable Insect Updates

David Owens, Extension Entomologist, and Bill Cissel, Extension Agent – Integrated Pest Management;

by David Owens
Earworm larvae and loopers are present in lima bean and snap bean fields. Lima bean thresholds are 1 corn earworm larva per 6 row-ft. Predatory insects are often abundant in beans, delaying worm treatment until a third of the larvae are ½ inch will help conserve predators. If you need to treat for loopers, be aware that pyrethroids perform poorly on this pest. Stink bugs and Lygus bugs are present. Stink bug thresholds are 7 per 50 sweeps and tarnished plant bugs are 15 per 50 sweeps.

Sweet Corn
by Bill Cissel and David Owens
We continue to catch large numbers of earworms in the pheromone traps. Monday trap capture can be found at (, and Monday trap captures were higher than last week’s from all sites. Thursday trap captures were slightly higher than Monday’s in most traps. As a reminder, what is reported on the web is on a per night basis, the table below is cumulative over Monday, Tuesday, and Wednesday night. Remember to rotate among chemistries; do not rely solely on pyrethroids. Also, be sure to treat any Bt sweet corn that does not have the VIP gene in it, earworms have demonstrated resistance to all other traits.

Trap Location BLT – CEW Pheromone CEW
3 nights total catch
Dover 4 48
Harrington 3 86
Milford 6 97
Rising Sun 0 31
Wyoming 2 94
Bridgeville 1 55
Concord 6 51
Georgetown 3 46
Greenwood 2
Laurel 2 117
Seaford 8 56