Water loss during cuticle sclerotization in the medfly Ceratitis capitata is independent of catecholamines

Insect cuticles undergo a striking water loss during the process of sclerotization. It has been considered that such dehydration is due to a physico-chemical displacement of the water due to incorporation of catecholamines. The dehydration of the puparium in the Medfly Ceratitis capitata throughout pupariation was studied. Water loss in the white pupa mutant, that fails to export catecholamines to the puparium, was not significantly different from that of the wild type or a melanic mutant strain, both with high content of cuticular catecholamines. These results are in clear contradiction to the catecholamine-displacement model for cuticle dehydration. An alternative model explaining the mechanism of water loss during sclerotization is proposed. Copyright (C) 1996 Elsevier Science Ltd