SEASONAL INFESTATION BY PINK-BOLLWORM, PECTINOPHORA-GOSSYPIELLA (SAUNDERS) OF TRANSGENIC COTTON, CONTAINING THE BOLLGARD(TM) GENE, PLANTED IN COMMERCIAL FIELDS IN CENTRAL ARIZONA

Bells from transgenic cotton NuCOTN 33 (Delta and Pine Land Co.), cont aining the Bollgard(TM) gene (Monsanto Co.) and from the parental cult ivar DPL-5415 were examined for fourth-instar larvae of the pink bollw orm (78,240 total bells). Bells from five paired fields were collected in the Queen Creek, Buckeye, and Gila Bend, AZ, areas, and a composit e of ten fields of each cultivar were collected in the Paloma Ranch ar ea near Gila Bend, AZ. Collections of 100 or 80 bells per field were m ade weekly from July through November 1995. Numbers of pink bollworm l arvae were very low in all fields through August and thereafter increa sed steadily in the control fields. Numbers of fourth-instar larvae in transgenic cotton were extremely low or zero throughout the season, e ven in fields which were adjacent to heavily infested control fields. Observations of infestations of the cotton leafperforator, Bucculatrix thurberiella Busck, in the paired field study also indicated greatly reduced leaf damage in NuCOTN 33 compared to DPL-5415. These results s how that NuCOTN 33 retained a high degree of efficacy for preventing t he development of fourth-instar pink bollworm larvae late in the seaso n into diapause. Most important, these data provide baseline informati on against which efficacy in subsequent years can be compared.