An artificial diet for rearing the spotted bollworm, Earias vittella (Fabricius) was developed under laboratory conditions (temperature 27 ± 1°C, RH 60 ± 5% and 16:8 h scoto /photophase regime). The diet ingredients consisted of wheatgerm (5 g), seeds of cotton (Gossypium hirsutum L. var. Pusa 8–6) (50 g) and chickpea (Cicer arietinitm L. var. Kabuli)(35 g) as base materials along with agar-agar (15 g), dried yeast powder (8.0 g), methyl-p-hydroxybenzoate (1.0 g), l-ascorbic acid (1.2 g), sorbic acid (1.0 g), cholesterol (0.2 g), streptomycin sulphate (0.2 g), and multivitamin multimineral and vitamin E capsules (one each). After rearing neonates on okra for 3–4 days, the diet supported the growth and development of E. vittella successfully for eight generations. Larval development on this diet was completed in 11.9 ± 0.66 days against 11.64 days on the pest's preferred natural host, okra (Abelmoschus esculentus) Moench. The growth and developmental indices on the artificial diet for the eight generations are reported.

At 25°C and 70% r.h. larvae of Spodoptera exempta develop faster and pass through five instars on star grass, Cynodon dactylon (L.); Pers. maize, Zea mais L.; and Kikuyu grass, Pennisetum clandestinum Chiov. whereas on guinea grass, Panicum maximum Jacq.; and Setaria plicatilis (Hochst.) Hack, the development is not only slower, but the larvae pass through six and seven instars, respectively. Samples of larvae reared on the former grass species suffer high mortality only at the first and the last instar stages so that the distribution of per cent mortality is U-shaped. On the latter host plants, the mortality during the first instar stage is equally high and continues through the subsequent instars with no obvious peak towards the end of the larval life. The samples on C. dactylon and Z. mais had much higher growth indices than those on P. maximum and S. plicatilis. C. dactylon is a preferred natural food plant of S. exempta in the field, and these investigations demonstrate its value and importance.