LETHAL ACTIVITY OF A TREHALASE INHIBITOR, VALIDOXYLAMINE-A, AND ITS INFLUENCE ON THE BLOOD-SUGAR LEVEL IN BOMBYX-MORI (LEPIDOPTERA, BOMBYCIDAE)

A trehalase inhibitor, validoxylamine A (VAA), gave a lethal effect in Bombyx mori larvae. Overall activities were reduced soon after inject ion of VAA at the 2nd day of the last instar larva. However, the letha l effect was found at the later stages. NMR analysis showed that treha lose was the main blood sugar and its level was strongly enhanced by t he VAA injection. It was supposed that utilization of the energy sourc e was prevented due to the trehalase inhibition, and consequently the overall activities were reduced. But, how the trehalase inhibition cau sed the lethal effect in the later stages remained unclear.