The insecticidal activities of materialsderived from Dryopteris crassirhizoma Nakai against third instar larvae of three species mosquitoes (Culex pipiens, Aedes albopictus and Anopheles sinnensis) were evaluated using a direct contact mortality bioassay.
The methanol extracts of D. crassirhizoma showed 100%, 87.8% and 100% larvicidal activity at 1,000 ppm against Cx. pipiens, Ae. albopictus and An. sinensis, respectively. Hexane fraction showed 100% larvicidal activity three species mosquitoes at 500 ppm after 24 hrs. Purification of the biologically active constituents from the hexane extraction with larvicidal activity was done using silica gel column chromatography. H1 and H3 fractions gave 100% mortality to Cx. pipiens, Ae. albopictus and An. sinensis at 100 ppm. H1 fraction separated with methanol to give a H111 through centrifugation. Fraction of the biologically active constituents from the H3 fraction with larvicidal activity was done using methanol. H31 fraction was determined 100% mortality to Cx. Pipiens, Ae. albopictus and An. sinensis at 50 ppm, respectively. Two fractions were analyzed C14H22O (H111, MW206.0) and C11H14O4 (H31, MW210.08) by GC and GC-MS. D. crassirhizoma derived compounds described herein could be useful for managing filed populations as larvicide of Cx. pipiens, Ae. albopictus and An. sinensis.