The emulsion and micro-encapsuled formulation from three essential oils, cassia, thyme white and lemon grass were tested for their insecticidal activities against Lycoriella ingenua (Dufour) adults at 0.3% concentration. As a result, the micro-encapsules than emulsion formulation was confirmed to show greater activity. Based on this result, insecticidal activities at several levels of concentration were examined, resulting in more than 80% insecticidal activity after 30 minutes at 0.6% level of cassia formulation. And also, insecticidal activity of three oil-based micro-encapsuled formulations lasted for up to 12 hours at 0.9% concentration. The main ingredients derived from three essential oils were evaluated on the insecticidal activity against Lycoriella ingenua. As a result, in case of thymol from thyme white, it showed more than 80% mortality after over 30 minutes at 0.25%, and in cinnamic aldehyde and citral, exhibited 88% and 82% mortality after 30 minutes at the 0.5% level, respectively. These three compounds were examined for whether the insecticidal activity was maintained depending on being over time. In case of thymol, it maintained good insecticidal activity against Lycoriella ingenua at 0.5% level until 120 hours, while cinnamic aldehyde and citral showed lower activity after 12 hours.