Counting nauplii and analysis of data
After 24 hours, the vials were inspected using a magnifying glass and the number of surviving larvae were counted. The percentage of mortality was calculated at each concentration. The concentration- mortality data were analyzed statistically. The effectiveness or the relationship of the plant product is usually expressed as a median lethal concentration(LCso) value which was determined using the Probit analysis method described by[7]. The LCso value represents the concentration of the chemical that produces death in half of the subjects after a certain exposure period. The percentage of mortality at each test dose and the control was determined by using the formula: