Strong insecticidal potential of methanol extract of Ferulago trifida fruits against Anopheles stephensi as malaria vector.

Many researchers have focused on controlling pest insects and vectors by natural products because of their low environmental pollution. The present study was conducted to evaluate the antioxidant and larvicidal activities of chloroform and methanol extracts of the leaves, fruits, roots, and isolated coumarin compounds (prantschimgin, oxypeucedanin, and 6-hydroxymethylherniarin) of Ferulago trifida from the Apiaceae family against Anopheles stephensi as one of the main malaria vectors. For insecticidal evaluation, A. stephensi larvae were exposed to different concentrations of the extracts and pure compounds (0.625-1280 ppm) according to the WHO protocol. The mortality percentages were measured 24 h after treatment and lethal concentration values were calculated. In addition, radical scavenging activities of the mentioned extracts and compounds were measured by the DPPH method. The methanol extract of fruits showed potent insecticidal properties with LC₅₀ and LC₉₀ values of 2.94 and 18.12 ppm, respectively. The chloroform extracts of the fruits and leaves were the second and third extracts with larvicidal effects. Among pure compounds, only oxypeucedanin showed moderate toxicity against A. stephensi with LC₅₀ and LC₉₀ values of 116.54 and 346.41 ppm, respectively. The antioxidant activities of the methanol extracts of leaves and fruits were stronger than other extracts with IC₅₀ values of 155.83 and 159.32 ppm, respectively. In conclusion, the methanol extract of F. trifida fruits can be used as a potent bio-insecticide in green control programs of mosquitoes, especially A. stephensi.