Reassessment of Some Amino Acid Requirements of Larvae of Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae)

Abstract

Dietary requirements of Oryzaephilus surinamensis (L.) for alanine, proline, cystine, and arginine were determined using a purified diet. Measurements of rate of survival and development showed that dietary components influenced amino acid requirements of the insect. Addition of alanine to the diet improved rate of survival or development, but only in the absence of nucleic acid. The indication that cystine is toxic to this insect under certain circumstances and that a concentration of 0.67% of arginine monohydrochloride in a diet containing nucleic acid is near the optimum was supported by the results. Requirements for lysine and methionine were apparently the same as had been reported previously. Alanine, arginine, and proline were among the bound amino acids of the nucleic acid used to supplement the basic diet, but cystine, lysine, and methionine were not. Until dietary nucleic acid can be replaced by substances of known composition, definitive dietary requirements of some amino acids cannot be determined.