Trehalose and trehalase were determined in the Tenebrio molitor L., using larva, pupa and imago. A total number of 895 animals was analyzed. A growth curve up to the end of the larval stage was established (Fig. 1) and compared with the normal one obtained by Fraenkel. It was shown that trehalose and trehalase are more concentrated in the larva and imago presenting a curve with two arms as depicted in the Fig. 3. Trehalase was expressed in mg/g of Tenebrio and trehalase in µg of glucose /mg proteín.