The LC20 of each plant extract was treated on adults by Potterfs spray (2 ml/100 insects). Controls were
treated with the solvent alone. After treatment, five females and two males (3-day old) were then introduced into
each vial (2 cm diameter, 10 cm high) with food (5 g/vial) and allowed to lay eggs for 5 days. Ten replicates were
set up for each compound and control. On the 5th day, all insects were removed and the eggs on grain in each
vial were counted. Thereafter, all emerged adults in each replicate were counted. Number of eggs and emerged
adults were then subjected to two-way ANOVA. Means were compared using the least significant difference
statistic (P.0.05) (SAS, 1988).