Technical Abstract: The stable fly, Stomoxys calcitrans, is one of the most significant pests of livestock in the United States. We are interested in the identification of targets for the development of novel control for this pest species, focusing on those molecules that play a role in successful feeding and reproduction. Using pyrosequencing technology, we have developed a database representing genes expressed at the immature and adult lifestages of the stable fly in an effort to identify such targets. We describe the characterization of several transcripts that may have a role in chemosensation, i.e. odorant binding proteins, chemosensory proteins, odorant receptor, gustatory receptor, as well as genes that have similarity to those involved in sex determination pathways of related Dipterans, i.e. transformer, transformer-2, and doublesex. We are optimistic that the current database will be a valuable tool for target identification and for comparative studies with other Diptera.