This EPA document is the final work plan for (Z)-9-tricosene (Muscalure) and includes the expected registration review timeline. (Z)-9-tricosene is an attractant pheromone registered for use to control house flies (Musca domestica), stable flies (Stomoxys calcitrans), eye gnats (Hippelates species), and horse flies (Tabanus species). (Z)-9-tricosene was classified as a biochemical pest control on May 5, 1989 because, even though chemically synthesized, it is identical to the sex pheromone of the feamle house fly. It is registered for use as a pest insect attractant in traps and, as such, has a nontoxic mode of action.