A highly palatable feed additive to prevent the development of stable flies and houseflies in the manure of treated horses. Larvastop, containing fly growth regulator Dimilin, breaks the fly life cycle by preventing the formation of fly larvae's exoskeletons when they molt (resulting in their death). Reduces fly populations by 97-100%. Start feeding in spring before flies begin to appear, and continue feeding throughout the summer. This product contains no organophosphates and can be used as part of an integrated pest management program.