Trehalase (EC. 3.2.1.28) activity has been studied during aging in male and female Callosobruchus analis beetles. Enzyme activity was much higher in females than males throughout adult life. Trehalase showed two peaks of activity in females, a small peak on the 3rd day and another on the 10th day after adult ecdysis, while males showed one peak only on the 10th day after emergence. Besides trehalase activity, trehalose as a percentage of total sugars, and mortality curves have been studied. It was found that the energy needs of the insects also increase as they age.