Deploying genetic technologies in insect genomes involves the expression of genes. There are a number of promoters that have broad host ranges but, in general, insect biologists, with some exceptions, do not have a deep selection of tissue specific promoters . Xu and colleagues have isolated and characterized the Vitellogenin promoter from Bombyx mori. The promoter-containing fragment is about 800bp and seems to respond as expected for a Vg promoter. It can be activated by 20-hydroxyecdysone and is expressed in a tissue-, stage- and sex-specific manner. This is a useful addition to the Lepidoptera toolbox.