Optimization of Soxhlet extraction of Ipomoea alba L. and evaluation of a botanical pesticide formulation

Ipomoea alba L. (Convolvulaceae) is a vigorously growing wild plant with potential as a source of botanical pesticides. This study optimized Soxhlet extraction of I. alba and evaluated a pesticide formulation containing its extract. Extraction time (150 - 300 minutes), plant material-to-solvent ratio (1:20 - 1:50, w/v), and ethanol concentration (50 - 96.5%, v/v) were examined. The highest extraction yield, 35%, was obtained after 240 min at a material-to-solvent ratio of 1:30 using 70% ethanol. A formulation containing neem leaf extract (3%), I. alba extract (7.5%), and niaouli oil residue (4.5%) produced 80% mortality within 3 hours in a spray assay. In a food-dipping assay, mortality reached 70% after 24 hours and 80% after 36 hours.