Anti-Insect Activity of the Methanol Extracts of Fern and Gymnosperm

With environmental and food safety issues becoming one of the greatest concerns of the public, active plant compounds play more and more important roles in pest controlling. Fern are of great significance for application as new pesticides due to their particular status in plant taxology and co-evolution with insects. In this study, methanol extracts were distilled from wild fern and gymnosperm of 54 species of 22 families collected from Shiwandashan Mountain in Guangxi Zhuang Autonomous Region of China. Insecticidal activities of the methanol extracts were assayed on both adult house fly (Musca domestica) and mosquito (Aedes albopictus). Significant insecticidal activities were exhibited in the methanol extracts of five species, Cupressus funebris (leaves and stems), Cycas acuminatissima (roots), Keteleeria fortunei (leaves and stems), Onychium japonicum (whole plant), and Pinus taiwanensis var. Darning shanensis (leaves and stems). Applications of the extracts of these plants resulted in higher than 50% mortalities in 4th instar larvae of A. albopictus at 24 h after treatment. The methanol extracts from 13 species possessed insecticidal activities against the adult of M. domestica at 48 h after treatment with higher than 90% mortalities. The extensive screening results showed that these fern and gymnosperm were highly potential to be botanical insecticides. The findings provide a feasible and valuable basis for further investigation.