“…Nutritional and environmental factors affect digestive enzymes; the digestive proteolytic and amylolytic activities of Spodoptera littoralis, for example, are closely correlated with the protein level in the diet or with the environmental temperature (lshaaya et al, 1971). In some cases digestive enzymes can be used as parameters for assessing antifeeding activity Ishaaya and Casida, 1975;Ishaaya et al, 1974Ishaaya et al, , 1977Ishaaya et al, , 1980Ishaaya et al, , 1982, or phagostimulation (lshaaya and . Despite availability of ample information concerning biochemical properties of digestive enzymes in various insects (House, 1974;Wigglesworth, 1974), relatively little is known about their role in insect feeding and insect-host compatability.…”