Sulfur-Containing Amino Acids in the Nutrition of the Saw-Toothed Grain Beetle, Oryzaephilus surinamensis (L.) (Coleoptera:Silvanidae)

Abstract

The effects of the sulfur-containing and related amino acids on the survival and growth rate of saw-toothed grain beetles were investigated with a chemically defined diet. L-Cysteine can replace cystine in the diet of this organism. It is toxic to the saw-toothed grain beetle, but this toxicity can be reversed by including L-methionine in the diet. High concentrations of L-methionine in the diet are also deleterious to the organism. The optimal concentration in the diet is in the neighborhood of 0.56% of L-methionine. L-Methionine can be replaced, however, at least partially, by either L-serine or glycine in the absence of L-cysteine.