The Embryonic Development of Tribolium confusum

The basic embryogeny is described and a chronology of developmental events at 25.5±1°C is presented. The fundamental developmental pattern is not unusual for a beetle. The more notable events and structures include an apparently sperm-filled tubular structure (possibly a micropyle) found on the chorion of some eggs. Peripheral energids of the presumptive blastoderm exhibit annular waves of mitoses. The mesenteron develops from a pair of posterior rudiments. An eosinophilic serosa secretes a thick external cuticle. The well-developed pleuropodia are believed to produce secretions that lyse the serosa and the serosal cuticle. Centrifuged eggs develop, indicating that the embryos have some regulative ability.