Novel peptide neurotoxins, α- and β-pompilidotoxins (α- and β-PMTXs), were purified from the venoms of the solitary waspsAnoplius samariensisandBatozonellus maculifrons.Their structures were analyzed mostly by MALDI-TOF-MS, which were corroborated by solid-phase synthesis. α-PMTX, with 13 amino acid residues and the sequence of Arg-Ile-Lys-Ile-Gly-Leu-Phe-Gln-Asp-Leu-Ser-Lys-Leu-NH2, greatly potentiates synaptic transmission of lobster leg muscle by the presynaptic mechanisms. β-PMTX, in which the lysine residue at 12 position of α-PMTX was replaced with arginine, was more potent than α-PMTX.