Extraction optimization of insecticidal compounds fromLysurus mokusinby response surface methodology

We optimized the extraction process ofLysurus mokusin(L.) Fr. insecticidal compound (LMIC) using response surface methodology with ultrasonic extraction (UE). The surface morphologies of maceration extract (ME) and UE residues were compared by scanning electron microscopy, and then the activity of LMIC onLymantria dispar(Asian gypsy moths) larvae was determined. Results showed that the optimal condition of UE was followed by 80 min of extraction time, 60% of ethanol concentration and 80 mL g(-1)of liquid-solid ratio. The surface morphologies of UE residue were looser and rougher than ME residue. The corrected mortalities of LMIC onL. disparlarvae was 59.77%. This result indicated thatL. mokusinwas a good candidate as pesticide for pest management.