David Owens, Extension Entomologist, owensd@udel.edu
Asparagus
Continue checking asparagus for beetles and eggs on emerging spears. A treatment may be recommended if 2% of spears are infested with eggs. Eggs will appear as small, black cylinders attached at a 90 degree angle to the spear.
Cole Crops
Continue scouting fields for imported cabbageworm and diamondback larvae. A treatment in the early stages of growth may be recommended if 5% of plants are infested. There are a large number of effective modes of action for worms. Pyrethroids and organophosphates should be saved until much later in the fall in order to preserve beneficial wasps. Wasps can destroy up to 70% of diamondback moth larvae and a large percentage of looper eggs. Over the course of the season, this can be a significant population moderator.
Melons
If watermelons are being moved outside to harden off, be sure to check them for aphids. If 20% of plants are infested with at least 5 aphids per leaf and beneficial insects are not actively working on the aphids, a treatment may be necessary. The easiest way to do treat is to treat the transplant tray with a neonic. Be sure to watch your rates, they are much lower than a field application. While checking plants for aphids, be sure to also check for stippling characteristic of spider mite infestation.