Nectariless plants of upland cotton, Gossypium hirsutum L., have shown some resistance to pink bollworm (PBW), Pectinophora gossypiella (Saunders). The nectariless trait has been transferred to Pima cotton, G. barbadense L. Pima nectariless cotton lines were compared with their nectaried counterparts and with each other for 1 to 3 seasons in large plots untreated with insecticide at the University of Arizona Maricopa Agricultural Center. For the first seasons, Pima S-6 nectariless averaged 34% less seed damage, but P-6 nectariless averaged 0% more seed damage caused by PBW than did 'Pima S-6'. In the 3rd season, on the basis of incomplete data, Pima S-6 nectariless had only 13% less seed damage, and P-6 nectariless had 33% less seed damage than did Pima S-6. The P-6 nectariless line did not have less seed damage than its nectaried counterpart, P-6, in the I season in which they were compared. These equivocal data cast some doubt on the value of nectariless as a PBW-resistance trait in Pima cotton.