Sitophilus oryzae is a major stored grain pest affecting many varieties of food grains, among which wheat infestation is common. It has been estimated that females of Sitophilus oryzae can destroy 50 g of stored grain in three generations. Quantitative loss was ascertained by infesting a fixed quantity of wheat grains with a fixed number of male and female pairs and taking the weight Sitophilus oryzae is a major stored grain pest affecting many varieties of food grains, among before and after the infestation. Qualitative changes concerning the loss of amino acid species upon infestation were ascertained by scanning the amino acid content in the pre- and post-infestation phases through double-dimensional chromatography. It has been found that the infestation caused weight loss in different varieties, but the losses were not uniform, such as while PB 1105 suffered the most (24.57%), Sonalika suffered moderate (19.96%), and Kalyan Sona suffered the least losses (11.96%). Similarly, the amino acid content also induced the attack. The chromatogram of the post-infested sample revealed that in the PB-1105 variety of wheat, six amino acids were lost, including two essential ones. Whereas, in Sonalika and Kalyan Sona, out of twelve amino acids, only three were lost, of which one was an essential amino acid.