show Abstracthide AbstractThe Mediterranean flour moth, Ephestia kuehniella (Lepidoptera, Pyralidae), is a worldwide storage pest being spread by international trade (Benson 1973). The country of origin is disputed, Asia minor is a good candidate as 18 of 60 species of Ephestia are occurring there (Richards and Thomson 1932). Flour moth larvae feed on cereals, cereal products, nuts, and dried fruit (CABI). Flour mills and bakeries are the primary sites of infestation, but households are often plagued too.A relatively short generation time of two to three months - given favourable ambient temperatures - is a good predisposition for spreading and infestation of a pest species. However, short generation time and low demands on breeding care make it also a useful laboratory species. Strains of the flour moth have been kept continuously in culture for more than 90 years. The flour moth has been widely used as a model species for studying developmental processes on the cell level and the gene-phenotype relationship especially between eye-colour mutants and the ommochrome synthesis pathway by Alfred Kühn and colleagues (1929–1963).Cytogenetically, E. kuehniella is a well-studied species. Investigations focused on interphase nuclei and meiosis with special emphasis on sex chromosomes. As in all Lepidoptera, the females are heterogametic and like in most Lepidoptera, they have a WZ sex chromosome pair, while males are homogametic and have a ZZ sex chromosome constitution. In interphase nuclei, the W chromosome forms a sex-specific heterochromatin body, called 'sex-chromatin' or 'W-chromatin'. It reaches conspicuous sizes in polyploid somatic tissues. W-chromatin bodies of more than 10µm diameter and consisting of several thousands of W chromosomes are present in the highly polyploid silk gland cells.E. kuehniella has become a model species for a new way of genetic pest control which has a potential to compete with conventional methods like fumigating and heat treatment: the introduction of males with Z-linked non-allelic lethal factors on the two Z chromosomes to populations. This causes lethality in all offspring females as they receive only the lethal Z chromosome from their father.Previously, the mitochondrial genome of E. kuehniella has been published. Its W chromosome was sequenced from micro-dissected W chromatin bodies. Here we present the female and male genomes and pupal transcriptomes.