Horse flies, members of the Tabanidae family, are large, aggressive insects known for inflicting a particularly painful bite. Only the female flies bite, requiring a blood meal to produce eggs. These persistent pests are drawn to warmth, carbon dioxide, and movement, making humans and animals easy targets during warmer months. Managing horse fly populations around your property can be achieved through practical, non-chemical, home-based solutions focused on environmental control, natural repellents, and simple traps.
Modifying the Environment to Deter Horse Flies
Effective horse fly control begins with disrupting the insects’ life cycle by eliminating attractive breeding and resting sites. Female flies require moist environments, often laying eggs in or near standing water, damp soil, or areas with decaying organic matter. Regularly inspecting your property to remove stagnant water sources directly reduces the number of potential nurseries.
Managing organic waste is equally important, as decaying materials provide a rich food source for developing larvae. Promptly removing or composting these materials away from high-traffic areas prevents the flies from establishing a breeding presence near your home. Keeping vegetation trimmed removes the shaded, sheltered resting spots adult flies seek during the day.
Horse flies are strongly attracted to dark objects because these colors absorb solar radiation, mimicking the heat signature of a warm-blooded animal. To reduce attraction near your home, minimize the use of dark-colored outdoor furniture or equipment in sunny areas. Simple physical exclusion methods, such as ensuring all window and door screens are intact, will prevent stray adult flies from entering interior spaces.
Creating Topical and Area Repellents
Natural, homemade repellents offer a way to mask the host’s attractive scent and deter flies without using harsh chemicals. Many home remedies rely on strong-smelling botanicals, which flies find offensive and avoid. A topical spray can be created using a base of apple cider vinegar (ACV), which horse flies reportedly dislike due to its acidity and odor.
A standard recipe involves mixing two cups of ACV with one cup of water, then adding a few drops of dish soap to act as an emulsifier. The dish soap ensures the oils and water mix properly and helps the solution adhere to the skin or clothing for a longer duration. This mixture can be sprayed on clothing or applied to skin, though a small patch test is always recommended to check for sensitivity before full application.
Enhancing the basic ACV spray with essential oils boosts its repellent power. Strong, naturally derived deterrent properties are found in oils such as:
- Peppermint
- Eucalyptus
- Lavender
- Citronella
- Tea tree
For an area spray, combine 30 to 40 drops of your chosen oil blend with two cups of water and a half cup of witch hazel or white vinegar. This mixture can be sprayed around patio areas, doorways, and other outdoor gathering spaces for temporary perimeter defense.
For a non-vinegar perimeter defense, a simple garlic water spray can be utilized, as the pungent compounds in garlic are disliked by flies. To create this, crush several cloves of fresh garlic and infuse them in a pint of hot water overnight. Strain the liquid before spraying around the edges of outdoor spaces. Homemade repellents require more frequent reapplication, sometimes as often as every hour, compared to commercial products.
Building Simple DIY Traps
While environmental modification and repellents deter new flies, simple DIY traps are a method for actively removing adult flies already present in the area. These traps exploit the horse fly’s attraction to warmth, movement, and dark colors, which they mistake for a potential blood source. The most common design utilizes a dark, heat-absorbing object coated in an adhesive.
To build a sticky trap, secure a dark-colored object, such as a painted rubber ball or a black bucket, and hang it from a rope so it can sway slightly in the wind. The object should be placed in a sunny location to maximize heat absorption, which the flies detect with their infrared vision. Coat the entire surface of the object with a non-toxic, sticky substance like Tanglefoot or a thick mixture of petroleum jelly.
Another mechanical option is the funnel trap, which uses a two-liter plastic bottle. Cut off the top third of the bottle and invert it, placing it funnel-side down into the base. The inverted top creates an inescapable entrance for the flies.
This bottle trap works by luring flies with a sweet bait, such as a mixture of water, sugar or molasses, and a small amount of yeast. The flies enter the funnel, are drawn to the bait, and cannot navigate their way back out. Place these traps away from where people congregate, ideally 30 to 50 feet away, so they lure the flies away from your immediate area.