Guaiol, a natural product isolated and purified from the roots of Ferula ferulaeoides with insecticidal activity, shows significant inhibition of aphids at a concentration of 70 mg/L and good contact activities against the 4th instar larvae of Mythimna separate and 3rd instar larvae of Plutella xylostella, with LD50 values of 0.07 and 8.9 mg/larva, as well as fumigation activity against the 4th instar larvae of M.