Since 1992, burning of cotton gin-trash in Mississippi has been prohibited by clean-air laws. This has led to stockpiling and composting of gin-trash for later use as a soil amendment. The composting gin-trash has proven to be an ideal medium for stable fly development. Stable flies develop throughout the winter in gin-trash aided by the heat of decomposition. Cyromazine (Larvadex 2SL^R) by Ciba Geigy Corporation has given excellent stable fly control when incorporated into the gin-trash. Cyromazine was used in Mississippi under a FIFRA Section 24:C registration until mid December 1995. The registration was canceled at that time by the U.S. Environmental Protection Agency.