David Owens, Extension Entomologist, owensd@udel.edu
Second generation seedcorn maggot is extremely active. There are no rescue treatments for maggot damage. If your field is at risk and you are planting right into an attractive field (one with recent organic matter incorporation), and you have had a history of seedcorn maggot, you should consider an insecticide either as a seed treatment or an in furrow product.
Speaking of maggots, the insecticide Belay (Clothianidin; Valent) now has a 2(ee) recommendation for root maggot control in Brassica leafy vegetables. You can access the recommendation here: http://www.cdms.net/ldat/ld8J6003.pdf. It has a 3 week pre-harvest interval.