D3203: Impact of sorghum pericarp color on progeny production capacity of warehouse beetle, Trogoderma variabile

Sorghum is an important cereal grain crop grown globally for both food and fodder. Sorghum production has increased in the U.S. as a sustainable crop to enhance food security. However, stored product pests pose a significant threat to sorghum and other crops after harvest, causing 10-20% of annual food losses in the U.S.

Physiochemical properties of sorghum may influence its susceptibility to stored product insect feeding; however, not much is known about the types of plant defensive compounds that cause resistance to insect feeding in sorghum grain. Therefore, this study aims to understand whether grain from lines that are near-isogenic for genes that confer different pericarp colors and have different concentrations of anthocyanins have resistance to the warehouse beetle (Trogoderma variabile).

We measured the impact of feeding on three lines adult mortality, progeny production, developmental time, and progeny size. 20 Warehouse beetle adults were cultured on sorghum flours with either yellow, white, or red pericarp colors for one week. Adults were removed and mortality was assessed. Progeny were allowed to develop for 65 days post-treatment, at which point total progeny were counted across the three treatments and weighed. In a previous study, sorghum with red pericarp was more resistant to fungal pathogens. Therefore, we hypothesize that seeds with red pericarp will be less susceptible to feeding by stored product insects. Altogether, this research aims to identify factors associated with resistance to stored product insect feeding in sorghum, which will potentially enhance pest management strategies for stored product insects.