Samples of tritonymph individuals of Platynothrus peltifer were collected from two forest populations showing clear ecological and temporal divergences, and subjected to electrophoretic analysis of three enzymes, superoxide-dismutase, malate-dehydrogenase and esterases. Electrophoretic patterns were quite similar in both populations. This suggests that, after more than 40 generations, heterochronic differentiations do not seem to be related to allozyme alterations. Yet, a study of clonal diversity and its temporal modifications in both populations is required to confirm this hypothesis. © 1990.