Vegetable Crop Insect Scouting

Vegetable Crop Insect Scouting
David Owens, Extension Entomologist; owensd@udel.edu

Sweet Corn
Corn Earworm activity continues to slowly decline, but numbers remain elevated in several of our blacklight traps. They probably will maintain high enough populations to justify a 3 day spray schedule for the next week. Trap counts from Thursday are as follows:

Brassicas
Diamondback moth and beet armyworm appear to be more active than usual this season. Neither species is susceptible to pyrethroids. I like to use the softer contact materials until foliage becomes dense and heads begin to form and then switch to materials with translaminar properties. Adding an adjuvant with a spray material is a good idea because of the waxy leaves, just do not add a sticker to a diamide or spinosyn. Also scout for whiteflies in leafy brassicas, especially kale. The Southeast Vegetable guide includes an efficacy table. Of note, not all neonics are equal on whitefly. Knack, Coragen, and Exirel are also rated as excellent on whitefly. Of those, Coragen and Exirel also have good worm activity.

Tomatoes
Continue scouting for worms and stink bugs in late tomatoes. The best materials for stink bugs include dinotefuran and bifenthrin.

Spinach
Continue scouting for webworms and beet armyworms.

Lima Beans and Edamame
Soybean looper activity in soybean is unusually high this year. Scout for loopers in lima beans. Unfortunately, this is not always an easy pest to control. Lannate performed surprisingly well in a soybean trial this year, but its short residual meant that looper numbers resurged 10 days after treatment. Intrepid, Blackhawk, Radiant and Avaunt are the most likely materials to have good looper control.