Spider mites have gone from an occasional to a serious pest in cotton in the Delta states. In 2010, producers in Mississippi treated 38 percent of their acreage for the pest. Angus Catchot, entomologist with the Mississippi State University Extension, says that with the increase have come questions about how much damage the pests are causing and when growers should spray for mites. He reported on research at Mississippi State and the other four land grant universities in the Delta region during the Cotton Insect Control Conference at the Beltwide Cotton Conferences in Atlanta.