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Natural Fly Control by The Organic Cowboy™ — Barn Accessories (Our Natural Fly parasites are a time-honored tool in the battle against pest…)

Natural Fly Control by The Organic Cowboy™ ✓ Verified

Our Natural Fly parasites are a time-honored tool in the battle against pest flies, killing flies

Ready to control flies in your barn using nature's own predators instead of chemical sprays?

Reviewed by Ann Pruitt, InfoHorse.com · Updated May 2026
Natural Fly Control by The Organic Cowboy™ — Barn Accessories (Our Natural Fly parasites are a time-honored tool in the battle against pest…)
Natural Fly Control by The Organic Cowboy™ — Barn Accessories (Our Natural Fly parasites are a time-honored tool in the battle against pest…)

Our Natural Fly parasites are a time-honored tool in the battle against pest flies, killing flies long before they become adults that spread disease and bother you and your horses. Our harmless gnats-sized guys prey on and kill flies, like a predator, the natural way. And as you remove chemicals, fly pupa-devouring beneficial predators such as Hister Beetles can thrive and enhance the overall fly control at your horse barn.

Natural Fly Control by. undefinedThe Organic Cowboy™

The Organic Cowboy™Our harmless gnats-sized guys prey on and kill flies, like a predator, the natural way-- no chemical sprays needed!

You’re on Your Way to Season-long Fly Control
Looking for a natural, yet effective method of Fly Control? The Organic Cowboy™has the answer! Our Natural Fly parasites are a time-honored tool in the battle against pest flies, killing flies long before they become adults that spread disease and bother you and your horses. Our harmless gnats-sized guys prey on and kill flies, like a predator, the natural way. And as you remove chemicals, fly pupa-devouring beneficial predators such as Hister Beetles can thrive and enhance the overall fly control at your horse barn... best of all, you won't notice you are there, until the flies start disappearing!

How Does It Work?


Step 1
– Locate Your Worst Fly Breeding Habitats

The primary fly breeding habitats in horse stables are those areas where manure builds up along fence lines (tough to clean up areas), and where manure is stored for later removal or handling. These are the primary fly breeding habitats and this is where you’ll find fly larva in large concentrations.

Step 2– Put Your Fly Parasites to Work

It’s now time to release your fly parasites and let them go to work for you. Working along the fence line, choose the areas of greater build-up, then simply peal open the top of the pack and shake out a small quan- tity of the fly parasites on to the manure. Continue with this process, until you’ve covered as much of the stable as possible. As the season progresses, you’ll begin to clearly recognize the worst fly breeding habi- tats. You should release your fly parasites there first, and then move to the secondary habitats. This is the same procedure you’ll follow with the arrival of each shipment of Organic Cowboy™Fly Parasites.

Step 3 – Maintain an Effective Program

Your fly parasites are now doing their job, but there are things you can do optimize your season long fly control. Along with releasing the proper number of fly parasites throughout the season, weekly stall and barn cleanup can greatly reduce the amount of fly breeding habitat and ef- fectively interrupt the fly breeding cycle. Cleanup and limited spray use in fly roosting habitats (where adult flies rest), can complement your biological fly control program. Just be sure never to apply the chemical sprays in areas where you release your fly parasites.

Whether you choose to receive your fly parasites every other week or monthly, be sure to release them within 48 hours of arrival. This helps you stay ahead of the flies, and insures that the fly parasites are fresh and ready for action. If you choose to store them for a few days, keep them refrigerated, to slow their metabolism.


A Little Science...

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 Cowboyblend 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.

Let Organic Cowboy™ Help You Get Started Today!


Organic Cowboy™ understands the needs of horse owners. Organic Cowboy™ was designed to be a highly effective and natural way to control flies to benefit both horses and the owners that love them. Call today and tell us about your property-- and we'll help you!



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The Solution Section (FAQ)
What are fly parasites and how do they control flies at a horse barn?
Fly parasites are tiny, harmless gnat-sized insects that prey on and kill pest flies the natural way, before those flies become adults that spread disease and bother you and your horses. The Organic Cowboy™ uses them as a time-honored biological tool in the battle against pest flies, with no chemical sprays needed.
Which flies do The Organic Cowboy™ fly parasites control?
The Organic Cowboy™ blend effectively controls house flies, stable flies, and horn flies. It combines three strains of fly parasites: Spalangia cameroni, Muscidifurax zaraptor, and Muscidifurax raptorellus, which target the pupae of these pest species.
How do I use fly parasites in my stable?
It is a simple three-step program. First, locate your worst fly breeding habitats, which are typically where manure builds up along fence lines and where manure is stored for later removal. Then peel open the pack and shake a small quantity of parasites onto the manure, working along the build-up areas, and maintain the program with regular barn cleanup throughout the season.
Where are the worst fly breeding spots in a horse barn?
The primary fly breeding habitats are areas where manure builds up along fence lines, which are often the toughest spots to clean, and where manure is stored for later removal or handling. These are where fly larvae concentrate in large numbers, so they are the first places you should release your fly parasites.
How soon do I need to release the fly parasites after they arrive?
Release your fly parasites within 48 hours of arrival to stay ahead of the flies and ensure the parasites are fresh and ready for action. If you need to store them for a few days, keep them refrigerated to slow their metabolism.
How often should I order and release fly parasites during the season?
You can choose to receive shipments every other week or monthly, releasing each new batch as it arrives to maintain season-long fly control. Pairing regular releases with weekly stall and barn cleanup reduces fly breeding habitat and interrupts the breeding cycle.
Can I still use fly spray if I release fly parasites?
Limited spray use in fly roosting habitats, where adult flies rest, can complement your biological fly control program. Just be sure never to apply chemical sprays in the areas where you release your fly parasites. As you remove chemicals, beneficial predators like Hister Beetles can also thrive and enhance overall fly control.
How do I get started with The Organic Cowboy™ for my property?
The Organic Cowboy™ understands the needs of horse owners and can help you build a natural fly control program tailored to your barn. Call 877.499.9190 to tell them about your property, or visit organiccowboy.com to get started.

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Ann Pruitt
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