Feed-Through Fly Control: A Practical Tool in the Fight Against Flies

Winter has been brutal in many parts of the country, but spring is on its way. You might be sighing with relief in anticipation of warmer weather and packing up your horse's heavy turnout blankets, but you're not the only one preparing for the change of seasons.

Spring also means fly season is right around the corner. Before flies make an appearance around your barn and pasture, take steps to lessen the fly population during the warm months ahead.

Adding a product like Farnam SimpliFly Feed-Thru Fly Control with LarvaStop* to your fly control program is an ideal first step.

How It Works

You've probably heard about feed-through fly control but aren't sure how it works. 

Female flies lay eggs in dark, moist areas, such as rotting organic matter — mainly manure — and those eggs develop into larvae and then mature into flies. When a horse is consistently fed a product like SimpliFly larvicide, the insect growth regulator in the pellets prevent the formation of fly larvae exoskeletons when they molt, resulting in their death. This interrupts the fly life cycle, thus limiting the population.

Some horse owners might be concerned about feeding a product that prevents fly larvae development, but there's no need to worry.  SimpliFly larvicide was formulated to work in the horse's manure and not in his body.

"The horse is really a 'mixing vat' and serves as the way to mix the product into the manure," notes Richard G. Godbee, PhD, PAS, Dipl. ACAS. Godbee is Director of Technical Services — Equine for Farnam, Vita-Flex and Horse Health. 

SimpliFly larvicide is not formulated to be absorbed from the horse's gastrointestinal tract. Its active compound (diflubenzuron) would not be expected to be digested or absorbed. 

The active ingredient in a feed-through fly control product can’t be mixed into the horse's manure without going through the process of ingestion and digestion first. The beauty of feed-through fly control is that the product is mixed into the horse’s manure simply by feeding it to him. Then when female flies come along and lay eggs in that manure, the larvae can't develop.

SimpliFly larvicide contains no organophosphates, insecticides that target the nervous system of insects and are highly toxic to both humans and wildlife. It’s the only equine feed-through fly control granted reduced-risk status by the EPA, which means you can feed it without worry.

How to Use It

SimpliFly larvicide is extremely palatable thanks to its alfalfa flavor, so horses eat it readily.

The amount fed is based on the horse's weight, so use a weight tape to get a close idea of how much your horse weighs. Then follow label directions to feed the correct amount by top-dressing or mixing it into your horse's feed each day.

It's the only equine feed-through fly control granted reduced-risk status by the EPA, which means you can feed it without worry.

"It's simple, so it fits into any feeding program, whatever forage or commercial feeds you're using, including senior and complete feeds," says Godbee.

Start your horse on Farnam SimpliFly Feed-Thru Fly Control as early as possible in fly season and feed daily to all horses on the premises. The product must be used continuously during fly season to be effective. 

One Tool in the Tool Box

As you're probably aware, success in the fight against flies requires a multi-zone approach. As effective as feed-through fly control products are, they don’t offer a complete solution since they don’t control adult flies.

"This is an extremely important part of the plan and is very easy to use because all you have to do is feed it, but you still need to treat horses for adult flies," says Godbee. 

Dealing with adult flies means following good management practices like regularly removing manure and using on-horse protection such as sprays, wipes and topicals and physical barriers like fly masks.

*Diflubenzuron
SimpliFly and LarvaStop are trademarks of Farnam Companies, Inc.