No CrossRef data available.
Published online by Cambridge University Press: 27 March 2009
Bollworms (Heliothis zea Boddie and H. virescens F.) are serious cotton pests. During 1980, the cotton crop in U.S.A. suffered an 8·73% loss due to insect pests; 3·07% of this loss was due to the damage caused by bollworms. This 8·73% loss in cotton production occurred despite control measures adopted by cotton growers at an average cost of $36.27 per acre (Anon. 1981). Four plant characteristics impart varying degrees of host-plant resistance against bollworms in cotton (Maxwell, 1977). The bollworm moths exhibit an oviposition nonpreference towards glabrous and nectarless cottons. Presence of high gossypol and ‘X-factors’ in plant parts detrimentally affects the growth and survival of bollworm larvae. The ‘X-factors’ are unknown chemical substances that impart host-plant resistance against bollworms in cotton. This resistance was shown to be heritable by Lukefahr et al. (1974).