Fly parasites are a species of parasitoids from the Pteromalidae family that are endemic to North America. These species-specific parasites lay their eggs exclusively in fly pupae, which serve as their host. Our Organic Cowboy blend of fly parasites includes Spalangia cameroni, Muscidifurax zaraptor, and Muscidifurax raptorellus. This mix of multiple strains effectively controls house flies, stable flies and horn flies.
Fly parasites spend their entire life cycle on or near the surface of manure and other decaying organic matter. When released near fly breeding sites, the female searches through the habitat like a predator, seeking out fly pupae. Upon locating a pupal case, she drums a hole, inserts her ovipositor, and deposits anywhere from one to a dozen eggs inside, depending on the species. She continues this process until all her eggs have been laid.
The lifespan of a female fly parasite ranges from as little as two weeks to about a month. She typically lives long enough to deposit 50 to 100 eggs. The eggs laid inside the pest fly pupae develop into mature adults within 14 to 28 days, leading to a new generation of fly parasites.
Additionally, eliminating chemical sprays allows natural beneficial predators to thrive. One key beneficial predator is the Hister beetle, which feeds on the egg, larval and adult stages of house flies.