Life fecundity tables of Earias vittella (Fabricius) on okra and cotton

Life table studies for Earias vittella (F.) on different hosts in the laboratory indicated that depending on survival values (I_x), the most suitable food for this insect species was okra seeds (0.89) followed by okra fruits (0.80), cotton squares (0.73) and cotton bolls (0.68). The net reproductive rate (R_o) of E. vittetla was highest in okra seeds (141.50) followed by okra fruits (124.17), cotton bolls (100.62) and cotton squares (99.32). The mean length of generation (T) ranged from 32.51 on okra seeds to 38.48 days on cotton squares. The highest values of innate capacity for increase in numbers (r_m) was 0.1523 on okra seeds and lowest (0.1195) on cotton squares. On the basis of r_m the food plants suitable for the pest were okra seeds (0.1523), okra fruits (0.1385), cotton bolls (0.1289) and cotton squares (0.1195) in descending order. On reaching stable age distribution, the population of E. vittetla at egg, larva, pupa and adult stages comprised 53.33, 39.59, 6.07 and 0.92 per cent on okra fruits; 54.99, 37.08, 6.96 and 0.93 per cent on okra seeds; 51.72, 41.55, 5.69 and 0.98 per cent on cotton bolls and 49.65, 43.76, 5.60 and 0.92 per cent on cotton sqnares, respectively.