DEVELOPMENT AND FECUNDITY OF SESAMIA-CALAMISTIS (LEPIDOPTERA, NOCTUIDAE) AND ELDANA-SACCHARINA (LEPIDOPTERA, PYRALIDAE)

The developmental rates and fecundity of two important African maize p ests, Sesamia calamistis Hampson and Eldana saccharina Walker, were st udied under constant temperatures and with two larval diets. Five temp eratures (150, 200, 250, 300 and 35-degrees-C) were used to investigat e developmental rates and three temperatures (20-degrees, 25-degrees a nd 30-degrees-C) were used in fecundity experiments. Larvae were reare d on maize stem cuttings and on artificial diet. The developmental per iod for S. calamistis on artificial diet required over 700 degree-days (DD); eggs needed 122 DD above a threshold of 9.7-degrees, larvae req uired 383 DD above 12.2-degrees-C and pupae 204 DD above 10.2-degrees- C. The developmental period for E. saccharina on artificial diet was 6 65 DD; eggs required 125 DD above 9.1-degrees-C, larvae 400 DD above 1 0.6-degrees-C and pupae 140 DD above 8.8-degrees-C. On artificial diet both species developed faster and had higher threshold temperatures f or larval development than when reared on maize stem cuttings. Pupal d evelopment rates did not differ between artificial diet and maize stem for either species, although developmental thresholds were marginally lower on artificial diet. S. calamistis averaged 250-690 eggs/female although some individuals produced more than 1000 eggs. Adult females lived 5.7 days at 30-degrees-C and 10 days at 20-degrees-C. E. sacchar ina females produce more eggs and lived longer than S. calamistis fema les. Average fecundity for E. saccharina was 470-620 eggs/female, but several individuals produced more than 1200 eggs. Adult females lived 6.6 days at 30-degrees-C and 14.6 days at 20-degrees-C.