Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu
Seed Corn Maggots (SCM) Control in Spring Planted Vegetables
We continue to observe flies actively laying eggs in a number of situations including recently plowed fields, especially when a cover crop is plowed under or when manure was applied to a field. Spring planted vegetables susceptible to maggot damage include cole crops, melons, peas, snap beans, spinach, and sweet corn. Control options can include commercial applied seed treatments, or soil insecticides; however, not all options are available for all crops. Please refer to the labels as well as the 2010 DE Commercial Vegetable Recommendations for control options.
Cabbage
As soon as plants are set in the field, begin scouting fields for imported cabbage worm and diamondback larvae. As a general guideline, a treatment is recommended if you find 5% of the plants infested with larvae.
Peas
Be sure to sample for pea aphids as soon as small seedlings emerge. On small plants, you should sample for aphids by counting the number of aphids on 10 plants in 10 locations throughout a field. On larger plants, take 10 sweeps in 10 locations. As a general guideline, a treatment is recommended if you find 5-10 aphids per plant or 50 or more aphids per sweep. In general, aphid development is favored by cool, dry weather which slows beneficial activity but is favorable for the development of aphids. Be sure to check labels for application restrictions during bloom.