Variation of cation concentrations in the haemolymph of the silkworm, Bombyx mori, with diet and larval-pupal development

Abstract

The concentrations of haemolymph cations were studied from the early 5th instar to a new pupal stage in the silkworm, Bombyx mori, reared on either mulberry leaves or an artificial diet. 1. 1. The potassium level in the haemolymph changed little during feeding and mature stage and] averaged 50 μequiv/ml in the silkworm larvae reared on both diets. It increased during larval-pupal development to 90 μequiv/ml at pupation. 2. 2. The magnesium level in the haemolymph of the silkworm larvae reared on mulberry leaves increased as the larval growth proceeded. On the other hand in the silkworm on artificial diet the level was maintained at a steady-state level of 100 μequiv/ml. In both groups it declined remarkably during larval-pupal development. 3. 3. The haemolymph sodium concentration was higher in the larvae on the artificial diet than those fed on mulberry leaves. 4. 4. The calcium level was higher in the larvae on the mulberry leaves diet than those on the artificial one during the feeding stage, reflecting the content of diets.