Abstract  [Objectives]  To identify components of volatile compounds of Piper nigrum and Zanthoxylum bungeanum, and determine the sensitivity of four caterpillar species to these compounds. [Methods]  Components of the active fractions of ethanol extracts from Piper nigrum and Zanthoxylum bungeanum were identified using bioassay-guided column chromatography and gas chromatography-mass spectrometry technologies. The deterrent effects of the major amide alkaloids derived from these two plants were tested on the larvae of four lepidopteran pest species; H. armigera, Spodoptera exigua, Mythimna separata, and Athetis lepigone, which have different ecological niches on summer corn crops. [Results]  The major amide alkaloid in pooled active fractions of P. nigrum was piperine (6.22%), whereas that in pooled active fractions of Z. bungeanum was various isomers of sanshool (8.32%). Generally, piperine was a stronger deterrent to feeding by pest larvae than sanshool (H. armigera：t₂₇=4.92, P<0.000 1; S. exigua: t₁₉=6.11, P<0.000 1; M. separata: t₁₅=9.15, P<0.000 1; A. lepigone: t₁₄=6.06, P<0.000 1). M. separata and A. lepigone larvae were the most sensitive to piperine, whereas those of H. armigera were least sensitive to this compound. In contrast, sanshool only significantly deterred feeding by S. exigua larvae. [Conclusion]  Piperine may be a suitable base compound for developing generic compounds to deter feeding by the larvae of Lepidopteran insect pests in summer corn fields. The ecological relevance and possible mode of action of amide alkaloids derived from the Piper genus is discussed in conjunction with our results.