Evaluation of cotton stalk destruction for control of pink bollworm (Lepidoptera: Gelechiidae)

Three cotton stalk destruction methods were evaluated for their impact on pink bollworm, Pectinophora gossypiella (Saunders), larval mortality. Cotton stalks were shredded using a rotary shredder, a flail shredder, and a forage harvester. The rotary and flail shredders left cotton bolls and shredded stalks in the field. The forage harvester removed much of the cotton residue from the field. The stalk shredding and harvesting treatments were evaluated for destruction of cotton bolls and pink bollworm larvae. Numbers of intact green bolls, intact dry brown bolls, and surviving pink bollworm larvae were similar for the three treatments. Pink bollworm overwintering survival levels in the field were similar for all stalk destruction treatments. Cotton plant residue was removed from the field with a forage harvester and evaluated for pink bollworm overwintering survival. Pink bollworm mortality exceeded 99.9% in shredded stalks from the forage harvester treatment.