Fig. 1

The life cycle of T. castaneum. A Face-to-face with a wild type Tribolium castaneum. B Ventral view of a male under dark field illumination. White eyes (vermilion mutant) allow for sensitive detection of transgene eye markers. The size of an adult beetle is 3.5 mm (length). C Life cycle of Tribolium: eggs are laid into the substrate (flour) and embryonic development takes 3 days at 32 °C. Only two out of a variable number of larval stages (ca. 7) are depicted. The pupa libera allows visual inspection of external structures facilitating phenotypic studies of metamorphosis. Female beetles need a few days after hatching until they start laying eggs, which they continue for 3–4 months (drawings not to scale). Life cycle sketch by Benjamin Schwarz