What’s New on the Ranch

Recommend the Organic Cowboy to a friend or neighbor, and when they order, we’ll send both you and your friend an extra order of fly parasites. You and your neighbor will recieve a double order... read more

Helpful Tips from Horse Owners

The Organic Cowboy is always looking for input from fellow horse lovers on how they are using fly parasites to create a successful control program. We share some tips and feedback on usage to help you create... read more
Organic Cowboy - Biological Fly Control

Meet the Pteromalidae Family

Fly parasites are a species of parasitoids from the Pteromalidae family and they are indigenous to North America. They are a species-specific parasite, laying their eggs exclusively in fly pupa – the host. The Organic Cowboy blend of fly parasites includes Spalangia cameroni, Muscidifurax zaraptor, and Muscidifurax raptorellus. This mix of multiple strains provides you the ability to control houseflies, stable flies and horn flies.

Fly ParasiteFly parasites live their entire life cycle on or near the surface of manure and other decaying organic matter. When they are released on or near fly breeding sites, the female searches through the habitat seeking out fly pupa. After locating one, she drums a hole in the pupal case, inserts her ovipositor, and deposits from one to a dozen eggs inside (depending on the species of fly parasite). She then moves on repeating this process until all her eggs have been deposited.

The life span of the female fly parasite ranges from as little as two weeks to as long as one month. She will live just long enough to deposit all of her 50 to 100 eggs. The eggs that were deposited inside the pest fly pupa will develop into mature adults within 14 to 28 days and a new generation of parasites emerges.

Biological Control of Flies - University of Kentucky