Influence of some maize cultivars lines (Zea mays L) on biological characters of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae)

Five maize cultivars and lines; Michoacan 12, BS 13, Passat, Pool 6 and OH 43, were evaluated, under laboratory conditions, for the influence on a number of biological characters, including mortality, growth and development, of the African armyworm, Spodoptera exempta L. (Walker) (Lepidoptera: Noctuidae). Overall larval mortality ranged from 36% (Pool 6) to 63% (OH 43). Larvae reared on Michoacan 12 and Pool 6 were significantly heavier than those reared on BS 13. Michoacan 12, Passat and Pool 6 supported significantly shorter larval durations (for mixed sexes) compared with BS 13. Larvae feeding on OH 43 supported longer larval durations than on the other cultivars. Female pupae from larvae reared on OH 43 were significantly lighter compared with those reared on the other cultivars while those from larvae reared on Michoacan 12 were significantly heavier than males. Pupae from any of the five cultivars showed no significant differences in duration for mixed sexes. However, within Michoacan 12, BS 13 and Pool 6 cultivars, male pupae had significantly longer durations than females. Pupal mortality was significantly different among cultivars. Insect growth indices were positively correlated with overall larval survival for ail cultivars. Implications of the results for the control of S. exempta are discussed.