Respiration rates of larvae, pupae, and adults of the black carpet beetle, Attagenus megatoma (F.), were determined at 28°C by using a differential respirometer. Respiration of male and female larvae increased through the 1st 80-100 days of development when rapid feeding and growth occurred. Peak mean values were 14.6 μliters O2/larva per h for males and 17.6 μliters O2/larva per h for females. Respiration then declined steadily to relatively low rates until the larvae were ca. 200 days old when another increase occurred. This latter increase was not associated with an observable increase in mean larval weight. Male and female pupae exhibited typical U-shaped respiration curves. Adult respiration reached peak mean rates at 5-7 days post-eclosion of ca. 13μliters O2/adult per h for males and 19 μliters O2/adult per h for females. Respiration rates of larvae isolated from food for 74 days dropped to 13% of the values for identically aged fed larvae. Growth curves and respiratory patterns of A. megatoma larvae indicate that an obligatory larval developmental arrest occurs that lasts for 3-4 mo or nearly ½ the larval developmental period.