The distinctive dark glands covering most of the aelial parts of the cotton plant are well known to growers. These glands contain an oil rich in insecticidal terpenoid compounds and as a consequence are associated with host plant resistance. The glands are a general characteristic of the tribe Gossypiae which, in addition to the cultivated species, includes many wild cottons of no commercial importance. Approximately sixteen wild cottons occur in Australia, probably the best known being Sturt's Desert Rose (Gossypium sturtianum), the floral emblem of the Northern Te1Titory. Whilst this species has been studied in some detail, in particular with respect to its potentially useful glanded plant/glandless seed trait, detailed studies of the chemistry of Australian wild cottons generally, have not been reported. Anecdotal evidence suggests that many of the native species are relatively free of insect infestation in the wild. In association with other work assessing the pest resistance of G. hirsutum varieties, a small plot of wild cottons was grown at Nai.Tabri over the 1993/94 season. The plot was unsprayed and plants were used in bioassays which measured the growth and survival of Helicoverpa larvae throughout the season. Preliminary results of these bioassays are presented here.