A nematicidal agent comprising as an active ingredient any of N-2-(pyridyl)ethylcarboxamide derivatives or salts thereof, the derivatives represented by the general formula: (I) wherein Ar is, for example, a substituted phenyl having one or more substituents, optionally identical with or different from each other, selected from the group consisting of a halogen atom, C1-C6 alkyl, halogenated C1-C6alkyl, C1-C6 alkylthio, halogenated C1-C6 alkylthio, C1-C6 alkoxy and halogenated C1-C6 alkoxy each of Xs independently is a hydrogen atom, halogen atom, C1-C6 alkyl, halogenated C1-C6 alkyl, etc.and n is an integer of 0 to 4. Further, there is provided a method of controlling nematodes by the use of any of these compounds. These nematicidal agent and method of controlling nematodes attain reduction of load on global environment, exhibition of a wide control spectrum with low dosage and exhibition of excellent control efficacy.
