Starch gel electrophoresis with L-leucyl-beta-naphthylamide as substrate revealed five aminopeptidases in extracts of Polistes versicolor. These enzymes are presumably products of five structural gene loci. All but Lap1 aminopeptidases exhibited differential distribution in the developmental stages and in the tissues. Five dipeptidases were revealed with different dipeptides. These enzymes exhibited significant differences in their substrate preferences, but a more homogeneous distribution throughout ontogenetic developmental stages than did aminopeptidases. Electrophoretic variants of Lap4 and PepA2 were detected and although a low intralocus heterozygosity was found due to the low frequency of these variants, phenotypical segregation observed at these loci in pupae extracts of some colonies points to the occurrence of more than one egg-laying female. Otherwise, the detection of Lap4 allozyme restricted to nests of one area suggests low dispersion ability of the adults of Polistes versicolor.