Daily ingestion and utilization of various kinds of nutrients by the silkworm, Bombyx mori (Lepidoptera: Bombycidae)

The contents of various kinds of nutrients in mulberry leaves and in the feces excreted by larvae of the silkworm, Bombyx mori, were determined, along with the daily amount of ingestion and utilization of protein, amino acids, carbohydrates, minerals, vitamins, sterols and fatty acids in the larvae.The amount of energy ingested and absorbed daily by the larvae was 1.005 and 0.466 kcal/g of body weight, and the amount of protein (expressed as amino acids), carbohydrates, and lipids (expressed as triglycerides) absorbed daily was 48.0, 28.2 and 6.32 mg/g of body weight, corresponding to 0.281 kcal, 0.107 kcal and 0.0566 kcal/g of body weight, respectively. These calorific values of protein, carbohydrates and lipids corresponded to approximately 60%, 23% and 12% of the total energy absorbed daily per gram of body weight of the larva. The contents of various kinds of nutrients in mulberry leaves and the daily amount of nutrients ingested and absorbed by the larvae were discussed in relation to the quantitative requirements of nutrients in the silkworm.