Abstract
Insect infestation of wheat, maize, and sorghum grains, caused by Trogoderma granarium Everts and Rhizopertha dominica Fabricius separately and in mixed populations, resulted in substantial changes in grain contents. At the highest infestation level (75%) both insects caused a significant (P < 0.05) decrease in crude fat and total carbohydrates, and an increase in moisture, crude fibre, and total protein contents compared to the control and lower levels of infestation. However, the differences in the levels of chemical constituents of grains as a result of differing feeding habits of the insects were not significant. Mixed populations of both insects produced intermediate results. Storage of these three cereal grains for one to four months in insect-free conditions did not result in any significant changes in any of the constituents examined.