Characterization of larval salivary glands from the stable fly, Stomoxys calcitrans

The stable fly is a pest of veterinary and economic importance, with damages in the United States estimated at $1 billion USD/year. Current control approaches have mostly been directed towards the adult stage of the fly, but control of the larval stage by identifying and treating larval habitats has been suggested. In an effort to understand the biology of stable fly larvae, as it relates to identifying behaviors or pathways that can be targeted for control application, we evaluated salivary glands dissected from third instars. Soluble proteins from larval salivary glands were resolved and revealed 15 predominant polypeptides with a single, ~80 kilodalton protein that was highly abundant. The enzymatic and antimicrobial activity of larval salivary glands was also evaluated, and we compare these results with data available for other blood-feeding insects, of whom also have non blood-feeding larval stages.