Abstract A dietary requirement for l -arginine by larvae of the saw-toothed grain beetle, Oryzaephilus surinamensis (L.), was demonstrated. Based on criteria of survival to the pupal stage, adult emergence, and length of development period, the optimum concentration of l -arginine in the diet was shown to be about 0·67 per cent. The arginine requirement of this organism could be satisfied by substitution with two or three times the equimolecular amount of l -citrulline. l -Ornithine could not replace l -arginine in the diet and was inhibitory even in the presence of more than a minimal concentration of l -arginine. Although creatine could be substituted to some extent for dietary arginine, the results suggest that this is not necessarily the end-product of arginine metabolism in this organism.

Larvae of the saw-toothed grain beetle, Oryzaephilus surinamensis, require l-arginine for survival and development, and can be satisfied by substituting with l-citrulline, but not l-ornithine.

Quantitative l-arginine requirements of larvae of the saw-toothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera, Silvanidae)☆

Key Takeaway: Larvae of the saw-toothed grain beetle, Oryzaephilus surinamensis, require l-arginine for survival and development, and can be satisfied by substituting with l-citrulline, but not l-ornithine.