Vegetable Crop Insect Scouting

David Owens, Extension Entomologist,

Seedcorn Maggot
Seedcorn maggot first generation adults are active. If planting in a field that has had recent cover crop incorporation, a seed treatment may be warranted.

Cole Crops
Continue scouting for imported cabbageworm and aphids. Worm thresholds are based on plant growth stage. During the seedling and early transplant stage, treat when 20% of plants are infested. Prior to cupping or early head initiation, thresholds are 30%. Adjuvants to help spread droplets and stick them to the waxy cuticle will help improve coverage and efficacy. Aphid thresholds are based on % of infested plants or % infested leaves. If more than 10% of plants are infested, a treatment may be advisable, or if 20% of leaves have aphids. Cabbage aphids are generally not as problematic at the beginning half of the season, in part because coming hot weather reduces their reproduction.

Melon aphids are active in various crops, including cucurbit transplants. This spring has also been favorable to pea aphids in alfalfa. If you have vegetables for which aphids are especially problematic, such as spinach, be sure to scout them carefully.

Corn Earworm Management in Sweet Corn Needs Assessment Survey
Dr. Kelly Hamby, Associate Professor/Extension Specialist with the Department of Entomology at University of Maryland, is leading a team of researchers who have developed a survey to prioritize research and extension efforts for improving corn earworm management in sweet corn throughout the Northeast. We appreciate your participation in this survey and will use results to develop a grant proposal targeting federal funds to address these needs.

Survey link: