Nutrition and feeding behavior of the southwestern corn borer Diatraea grandiosella Dyar (Lepidoptera : pyralidae)

The aim of the study was: 1) to determine the nutritional requirements of the southwestern com borer for proteins, carbohydrates, lipids, minerals and vitamins, 2) to measure the effects of carbohydrates and lipids on the feeding behavior of the first stage larva, 3) to distinguish positive or negative influences of nutrients on feeding behavior from those of lesions in absorption or metabolism so as to avoid incorrect decisions about growth responses, and 4) to study the inhibitive effects of hypocholesterolemic agents including 20, 25-diazacholesterol and triparanol on the sterol metabolism of the corn borer. The results indicated that the com borer has a specific dietary requirement for proteins, carbohydrates, sterols, polyunsaturated fatty acids, minerals, ascorbic acid and B-vitamins. The factors that are present in wheat germ oil which promoted larval growth and permitted normal wing development were determined. Beta-sitosterol acted as growth factor while methyl linoleate or linolenate served as wing development factor. The nutrients having a positive, neutral or negative influence on the maintenance of larval feeding were determined. The inhibiting effects of hypocholesterolemic agents on the sterol metabolism in the corn borer were determined.