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 sc lerotization. It has been considered that such dehydration is due to a physico-chemical displacement of the water due to incorporation of ca techolamines. The dehydration of the puparium in the Medfly Ceratitis capitata throughout pupariation was studied. Water loss in the white p upa mutant, that fails to export catecholamines to the puparium, was n ot significantly different from that of the wild type or a melanic mut ant strain, both with high content of cuticular catecholamines. These results are in clear contradiction to the catecholamine-displacement m odel for cuticle dehydration. An alternative model explaining the mech anism of water loss during sclerotization is proposed. Copyright (C) 1 996 Elsevier Science Ltd