Effect of fenvalerate-20EC on sericigenous insects. II. Digestive enzymes in the nutritive physiology of silkworm, Bombyx mori L.

Changes in the activities of a few digestive enzymes after fenvalerate-20EC treatment were studied during the late stages of multivoltine and bivoltine silkworms, Bombyx mori. Insecticide treatment induced a reduction in the activity of such enzymes as amylase, sucrase, and protease, whereas the trehalase activity was enhanced when the midgut was used as the source of enzyme. The changes recorded in the activity of these enzymes indicated probable adverse effects of fenvalerate on silkworm metabolism through interference with the functional abilities of digestive enzymes.