Will Fly Spray Kill Bot Eggs

Will Fly Spray Kill Bot Eggs? Debunking the Myth

by | Jul 9, 2023 | Equine Health, Equine Treatment

Fly infestations are a common headache for many horse owners during the warmer seasons. A particularly irksome fly variant, the bot fly, can lay its eggs on a horse’s fur. These eggs can then enter the horse’s system when it grooms itself, leading to a parasitic infection that is undesirable, to say the least. The question that many horse owners grapple with is: can fly sprays kill bot eggs? We’re here to debunk the myth.

What are Bot Eggs?

Bot eggs are the eggs laid by female bot flies, specifically on a horse’s fur. Bot flies are devious little creatures that utilize the horse’s natural grooming behavior to complete their life cycle. The female bot fly glues her eggs onto the horse’s hair—often on the legs, neck, or belly. When the horse grooms itself by licking or nibbling at its fur, the eggs get ingested. Inside the horse’s mouth, these eggs hatch into larvae, which then attach themselves to the lining of the horse’s stomach or intestines.

What About Fly Spray?

Fly sprays have become a common tool in the equine care arsenal, used to repel the pesky flies that irritate our beloved equines. Products like Farnam Endure Sweat-Resistant Fly Spray for Horses, and Absorbine UltraShield EX Insecticide & Repellent are popular among horse owners for their effectiveness in keeping flies at bay.

However, the claim that these sprays can kill bot eggs is indeed a myth. The primary function of these sprays is to deter flies from landing and biting horses. While many of them are designed to kill adult flies on contact, they do not have the ability to penetrate and kill bot eggs that are already glued onto the horse’s hair. Bot eggs have a tough outer shell designed to withstand the horse’s grooming and environmental factors, including the chemicals found in fly sprays.

Misconception Dispelled

In short, fly spray is not the cure-all solution for bot eggs. The eggs, once attached to the horse’s fur, are notorious for their resilience. They stick fast, have a tough exterior, and are impervious to most external factors, including the chemicals in fly sprays. So, while fly sprays do an excellent job of protecting your horse from fly bites and the resulting irritation, they do not possess the capability to kill bot eggs.

However, this doesn’t mean that the fight against bot flies is lost. For removing bot eggs, manual methods are the most effective. A bot knife, like the Tough 1 Bot Knife or the Roma Bot Egg Knife, can be used to scrape away the bot eggs from the horse’s fur. These special tools are designed to remove bot eggs without damaging the horse’s skin or coat. Regular grooming can keep the bot egg population under control. Combining this with the use of fly sprays like the Pyranha Wipe N Spray Fly Protection, which also provides a shiny coat to your horse, can provide an integrated approach to fly and bot fly management.

It’s important to remember that managing flies and their pesky bot egg-laying counterparts requires consistent and comprehensive efforts. Though fly sprays play an essential role in this management, they cannot singlehandedly defeat the problem of bot eggs. Knowledge is power—now that we’ve debunked this myth, horse owners can strategize more effectively to protect their equine friends from the nuisance and potential harm posed by flies and bot eggs.

Further Steps in Bot Egg Management

The debunking of the fly spray myth is not a call for despair but an opportunity to explore and adopt effective measures to control bot eggs and flies. Grooming tools, like the Epona Gummy Mitt, are great for removing the eggs from the horse’s hair. Yet, these are not the only defenses in the fight against bot fly infestations.

A crucial aspect of managing bot eggs is understanding the bot fly’s life cycle. Bot flies typically lay their eggs during the warmer months, but the larvae can survive within the horse’s digestive tract through the winter. Come spring, the mature larvae are expelled with the horse’s feces and pupate in the soil, hatching into adult flies ready to continue the cycle.

This lifecycle insight means horse owners can intervene at different stages. Regular deworming, especially after the first hard frost, can be an effective way to rid the horse’s system of overwintering larvae. Dewormers like Bimeda Equimax Horse Wormer, or Durvet Ivermectin Paste Dewormer, are very effective against bot fly larvae. As always, a vet should be consulted to establish the most effective and safe deworming regimen for your horse.

Moreover, maintaining cleanliness in stables, fields, and the overall horse environment is essential. Regularly removing horse feces disrupts the life cycle of the bot fly by limiting the locations where larvae can pupate. Equine Fly Traps, like fly strips, can help by trapping adult flies, reducing the population and, in turn, the number of eggs laid.

Related: Barn Fly Control Strategies and Tips

A Multifaceted Approach

Clearly, fly sprays are only one part of the bigger picture when it comes to managing bot flies and their eggs. This comprehensive approach—combining the use of fly sprays, grooming tools, dewormers, and good stable hygiene—provides the best defense against these parasitic nuisances.

While fly sprays can protect your horse from the irritation caused by fly bites, remember that these do not work against bot eggs. For bot eggs, the combination of regular grooming using specialized tools, seasonal deworming, and maintaining a clean environment will go a long way in keeping bot flies at bay.

Related: Barn Fans for Heat and Fly Control: Top Product Recommendations


Our myth is officially debunked—fly sprays will not kill bot eggs. But with the right information and a multifaceted approach, horse owners can effectively manage these parasites. And while each measure contributes to bot egg control, they work best in conjunction. So, go ahead and arm yourself with a quality fly spray, grooming tools, and dewormers, and don’t forget the importance of a clean environment. Your horse will thank you for it.

About The Author

<a href="https://www.equiniction.com/author/issabella-m/" target="_self">Issabella Mitchel</a>

Issabella Mitchel

Isabella is a remarkable equestrian and racehorse trainer, hailing from the horse capital of the world, Kentucky. Growing up in the heart of bluegrass country, she developed a deep affinity for horses from an early age.

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