The genome of the model beetle and pest *Tribolium castaneum* has been sequenced, revealing insights into its evolution and biology. *Tribolium* is a member of the most species-rich eukaryotic order, serving as a powerful model for studying insect development and pest control. The genome is highly expanded in odorant and gustatory receptors, P450s, and other detoxification enzymes, reflecting its ability to interact with diverse chemical environments. Development in *Tribolium* is more representative of other insects than in *Drosophila*, with retained ancestral genes involved in cell-cell communication. Systemic RNA interference in *Tribolium* functions differently from in *Caenorhabditis elegans* but offers similar power for gene function elucidation and target identification for selective insect control. The genome sequence and organization, gene content, and specific gene sets are detailed, highlighting the evolutionary and functional significance of various genes and pathways. The study also identifies potential pesticide targets and genes relevant to pest biology, vision, and taste. The expansion of chemoreceptors and detoxification genes suggests adaptation to a dry, chemically diverse environment. The genome sequence provides a rich resource for understanding beetle biology, physiology, and behavior.The genome of the model beetle and pest *Tribolium castaneum* has been sequenced, revealing insights into its evolution and biology. *Tribolium* is a member of the most species-rich eukaryotic order, serving as a powerful model for studying insect development and pest control. The genome is highly expanded in odorant and gustatory receptors, P450s, and other detoxification enzymes, reflecting its ability to interact with diverse chemical environments. Development in *Tribolium* is more representative of other insects than in *Drosophila*, with retained ancestral genes involved in cell-cell communication. Systemic RNA interference in *Tribolium* functions differently from in *Caenorhabditis elegans* but offers similar power for gene function elucidation and target identification for selective insect control. The genome sequence and organization, gene content, and specific gene sets are detailed, highlighting the evolutionary and functional significance of various genes and pathways. The study also identifies potential pesticide targets and genes relevant to pest biology, vision, and taste. The expansion of chemoreceptors and detoxification genes suggests adaptation to a dry, chemically diverse environment. The genome sequence provides a rich resource for understanding beetle biology, physiology, and behavior.