An illustrated guide to dissection and abdominal anatomy of the yellow mealworm beetle

using standard laboratory equipment. Our method emphasizes an aqueous immersion approach that preserves tissue integrity, enhances visibility, and yields consistent results. We describe the abdominal anatomy of both sexes, including the digestive, reproductive, and nervous systems. Structures include 6 testicular follicles, bean-shaped accessory glands, and a spermathecal gland in females that exceeds the spermatheca in size. The abdominal nerve cord comprises 7 metameric ganglia, with caudal fusion.