Red flour beetle, Tribolium castaneum (Herbst), larval developmental when fed mixed diet of 90% flour/10% yeast with different proportion of dried distillers grains with soluble

Protecting livestock feed from infestation by insect pests of stored products is a challenge with which feed facility managers and farmers commonly address. It becomes an issue of importance because insect consumption degrades the nutritional value of feed and contaminates the feed with insect parts and potential pathogens. Dried Distillers Grains with Solubles (DDGS), a co-product of the bio-fuel production process, is added to livestock feed because of its high nutritional value. As DDGS usage in animal feed increases, understanding the susceptibility of DDGS when mixed with livestock feed to insect pest of stored products is necessary for feed safe storage. The objective of this study was to determine the larval development of Tribolium castaneum on a mixed diet of 90% flour/10% yeast with different proportion of DDGS (10%, 20%, 30%, 40%, and 80%) compared to mixture of 90% flour/10% yeast at 32.5°C and 50% r.h. Our research has shown that DDGS as a raw ingredient is not a suitable food source for T. castaneum. However, by mixing different proportions of DDGS with flour and yeast, T. castaneum larvae grow as fast as when fed on flour/yeast alone (16.3 ± 0.3, 15.8 ± 0.3, 15.87 ± 0.3, 15.9 ± 0.1, 15.98 ± 0.2, and 16.95 ± 0.3d when feeding on 0, 10, 20, 30, 40, and 80% of DDGS mixed with flour/yeast respectively). Tribolium castaneum may be able to obtain sufficient nutrition from mixed material in feed other than DDGS allowing them to survive and thrive.