Daily Utilization and Consumption of Energy in Food by the Silkworm, Bombyx mori (Lepidoptera : Bombycidae)

Daily utilization and consumption of energy in food by the silkworm, Bombyx mori, were determined, and the quantitative distribution of the energy absorbed into the body of the larva, pupa, adult, and in the eggs and cocoon-shell was estimated. The amounts of energy ingested and absorbed during the 4th and 5th instars were 24.7 and 11.7 kcal for the male larva, and 28.5 and 13.6 kcal for the female, respectively. The rate of energy utilization was 47 to 48%. The average daily ingestion of energy was approximately 1.0 kcal/g of fresh body weight in both sexes during the larval stage and average daily absorption of energy was 0.49 kcal in both sexes. Energy gain in a larva was 6.7 and 7.9 kcal for the male and female during the same period. Energy consumption in relation to catabolism was 5.0 and 5.4 kcal/larva in the male and female, and the average daily consumption of energy was 0.18 and 0.17 kcal/g of fresh body weight for the male and female. The efficiency of storage of the energy ingested and absorbed in the larva, pupa and adult was also calculated. Approximately 25% of the energy absorbed was utilized for the formation of cocoon-shell and 10% was accumulated in the eggs.