Assessment of qualitative losses due to Sitophilus oryzae Linn. in differea maize varieties in storage De Debjani, Sarup Prakash, Head Division of Entomology, Indian Agricultural Research Institute, New Delhi-110 012 (India). Abstract The qualitative losses pertaining to total protein, tryptophan, amino acids, oli content, total sugar, and reducing and non-reducing sugar contents were estimated in 23–24 different maize varieties due to Sitophilus oryzae Linn, 60 days after storage. Irrespective of the maize varieties, viz, Basi local, VL-42, Antigua Gr. I, AEB comp. (white), AEB comp. (yellow), EBR comp., EHE 200486, EHE 200886, Pusa Arun, A-82, 5–1043, 5–1044, 5–1048, J-2028,J-3022 x JS, EC 8534, EC 8557, EC 8593, EC 8595, EC 8597, EC 85115, EC 85142 and EC 85144, there was an increase in the per cent protein content of the infested grains. This unexpected gain in protein content in all these maize varieties due to feeding by S. Oryzae was, perhaps, contributed by the presence of insect body fragments and frass. The loss in tryptophan content varied from 1.43 per cent in 5–1043 to 26.80 per cent in Basi local. Evidently, tryptophan is an essential constituent of maize grains in the nutrition of S. oryzae. In spite of insect damage in the susceptible or resistant varieties, viz., Pusa Arun and EBR comp., there was no set trend either in the per cent reduction or increase in various essential amino acids. The level of per cent reduction or increase of a particular essential amino acid in susceptible variety (Pusa Arun) was not equal to that of the resistant variety (EBR comp.). But the per cent increase or decrease of essential amino acids was quite substantial. Variety Madhuri yielded the highest oil content, Let, 11.45 per cent. The per cent loss in oil content varied from 0.89 in EHE 200486 to 2752 in AEB comp. (yellow) due to damage caused by S. oryzae in storage. There was a loss in the per cent total sugar content from 723 in J-1048 to 72.08 in EHE 200886, reducing sugar from 232 in EBR comp. to 46.00 in VL-42, and non-reducing sugar content from 7.46 in 5–1048 to 81.61 in EHE 200886, respectively. Top |