Amino Acid Requirements of Grain Beetles

Abstract

Development of a diet purified with respect to amino acids has led to the determination of amino acid requirements of several grain beetles. The confused flour beetle, Tribolium confusum (Duval), required (in per cent of diet) arginine, 0.5; histidine, 0.2; isoleucine, 0.5; leucine, 0.8; lysine, 0.56; methionine, 0.3 (0.15 with excess cystine); phenylalanine, 0.7 (0.4 with excess tyrosine); threonine, 0.4; tryptophan, 0.1; and valine 0.6. The red flour beetle, Tribolium castaneum (Herbst), required (in per cent) arginine, 0.4; histidine, 0.2; isoleucine, 0.3; and leucine, 0.7. The saw-toothed grain beetle, Oryzaephilus surinamensis (L.), required (in per cent) arginine, 0.3; histidine, 0.2; isoleucine, 0.3; and leucine 0.6. Other amino acid requirements for the latter 2 insects were not determined. Requirements of these grain insects are compared with those of other organisms. The confused flour beetle was tested as an assay organism for amino acid content of protein but showed little promise.