In greenhouse and field experiments, more than half of all 4-to 8-day-old, square-infesting, bollworm larvae,Heliothis zea(Boddie), were found on squares<6mm in diameter (measured at widest point on calyx). In terminal shoots from plants grown in the field in New Mexico, more than half of all 4-to 8-day-old larvae were found in squares<4 mm in diameter. Heavily damaged squares were nearly always<2 mm. In addition to the larvae in the squares, 25.6% of all larvae were found on leaves. Much of the heavy damage occurred as hollowed out squares which quickly dried out and were shed by the plant. Lighter damage was more evenly distributed across a range of square sizes. All parts of the square were consumed by bollworm larvae. Anthers and filaments suffered the heaviest damage.