No-Choice Study of Plant-Insect Interactions for Heliothis zea (Boddie) (Lepidoptera: Noctuidae) on Selected Cottons 1

Cotton plant-insect interactions were studied on selected upland cotton phenotypes in 1981 and 1982. Neonatal bollworm, Heliothis zea (Boddie), larvae were confined for 7 days in the field, using whole-plant cages. Results indicated that certain cultivars and breeding stocks were significantly more resistant than others, as shown by less bollworm damage to plant parts, and by reduced bollworm growth and survival due to antibiosis or feeding nonpreference. The glanded cultivars ‘CAMDE’ and ‘SP-21S’ and the breeding stocks ORSC, ORSBO, and HG-1 tended to be more resistant than the glanded ‘SP-37’ and the glandless stocks RDC-102 and STV-213 (gl). ‘Stoneville 213’ tended to be intermediate in resistance. Correlations of tannin quantity, relative astringency, and terpenoid content with bollworm growth, survival, and plant damage, showed that the highest correlations occurred between relative tannin astringency and all insect and plant damage parameters. Tannin relative astringency appears to be a useful method of screening cotton for bollworm resistance.