Changes in Crude Protein Content of Selected Pearl Millet (Pennisetum glaucum L.) Varieties Following Infestation by Sitotroga cerealella (Olivier)

Abstract

Sitotroga cerealella is one of the most destructive storage pests of pearl millet, causing deterioration in grain quality and nutritional composition. The present study evaluated changes in crude protein content of four pearl millet varieties before and after infestation by S. cerealella using the Kjeldahl method. Crude protein content increased in all varieties following insect infestation. The highest percentage increase was observed in the susceptible variety NDFB-3 (13.46%), followed by ICMB-155 (9.17%), ICTP-8203 (6.09%), whereas the resistant variety WCC-75 showed the lowest increase (5.36%). The apparent increase in crude protein is likely associated with the accumulation of insect-derived nitrogenous materials, including frass, exuviae and insect body fragments, together with carbohydrate depletion during feeding, rather than an actual improvement in nutritional quality. The observed trend suggests that resistant varieties undergo comparatively smaller biochemical alterations than susceptible varieties following insect infestation. These findings emphasize the importance of host plant resistance and effective storage management for maintaining the nutritional quality of pearl millet during storage.