What is the best way to repel deer flies and horse flies? The best approach involves using a mix of physical barriers, effective topical applications like natural insect repellent and commercial deer fly spray, and environmental management to reduce breeding sites. Addressing these pests requires a multi-faceted strategy focused on biting fly control.
Deer flies (genus Chrysops) and horse flies (family Tabanidae) are notorious summer pests. Their bites are painful because they slash the skin to lap up the blood. Getting rid of them or keeping them away from people and livestock is crucial for comfort and health. This detailed guide explores the most effective methods for outdoor fly control, from what you wear to what you spray.
Deciphering Deer Fly and Horse Fly Behavior
To fight these flies effectively, we must first know how they act. Both types of flies are strong fliers. They rely heavily on vision to find hosts. They are attracted to movement, dark colors, and exhaled carbon dioxide. Knowing this helps us choose the right defense.
What Attracts Biting Flies?
Flies use several cues to locate you or your animals:
- CO2: They detect the carbon dioxide you breathe out.
- Heat: They sense body heat.
- Visual Cues: They see movement and dark, contrasting colors.
- Chemicals: Certain scents on skin or sweat attract them.
Horse flies tend to hover before landing, often seeking large, dark targets. Deer flies are smaller and can be more aggressive in their pursuit.
Physical Barriers: Your First Line of Defense
Physical exclusion is often the simplest and safest horse fly deterrent. This works well for stationary targets like patios or resting animals.
Protective Clothing Strategies
Wearing the right gear makes a big difference. This is where fly repellent clothing comes into play.
- Light Colors: Wear light-colored clothing. Flies prefer dark colors. White, tan, or light gray reflects heat better and is less attractive.
- Coverage is Key: Cover up as much skin as possible. Long sleeves and long pants are best when flies are active.
- Head and Neck Protection: Use wide-brimmed hats. Consider a fine mesh head net, especially for gardening or fishing in high-fly areas.
- Tuck It In: Tuck shirts into pants and pants into socks. This stops flies from crawling underneath fabric to bite.
Barriers for Areas
If you spend time on a deck or porch, creating a physical barrier helps.
- Screened-in porches work perfectly.
- Using fans creates air movement that biting flies hate. They struggle to land in moving air. A simple box fan aimed at your seating area is a great, low-tech natural insect repellent method.
Chemical and Topical Defenses: Sprays and Repellents
When barriers aren’t enough, you need something applied directly to the skin or clothing. Choosing the right deer fly spray or horse fly deterrent is vital.
Synthetic Repellents
Commercial sprays are often the most powerful option for short-term protection.
- DEET: DEET (N,N-Diethyl-meta-toluamide) is highly effective against many biting insects, including some flies. Use it according to label directions, especially on children.
- Picaridin: Picaridin is another synthetic option. Some people find it less oily than DEET and it often works very well against biting flies.
Exploring Natural Insect Repellent Options
Many people prefer natural insect repellent options due to concerns about synthetic chemicals. These often rely on plant extracts.
Essential Oils for Biting Flies
Certain essential oils for biting flies have shown promise. These work by masking the scents that attract the flies.
| Essential Oil | Primary Active Compound | Notes on Efficacy |
|---|---|---|
| Lemon Eucalyptus (OLE) | PMD | Often rivals low concentrations of DEET. |
| Citronella | Citronellal | Classic repellent, needs frequent reapplication. |
| Geraniol | Geraniol | Highly effective against many biting insects. |
| Peppermint | Menthol | Strong smell deters many pests. |
| Rosemary | Cineole | Good secondary repellent when mixed. |
Homemade Fly Repellent Recipes: You can mix these essential oils with a carrier oil (like coconut or jojoba oil) or rubbing alcohol/witch hazel to create a topical spray. Remember, homemade fly repellent needs frequent reapplication—often every 30 to 60 minutes for best results.
- A basic dilution ratio is about 10-15 drops of essential oil per ounce of carrier. Always do a small patch test first.
Topical Applications for Livestock and Pets
Protecting animals requires specialized products, often strong biting fly control sprays formulated for larger areas and tougher skin.
- Pyrethrins/Permethrins: These insecticides are often used in premise sprays or spot treatments for animals. Always use products specifically labeled for the target animal (e.g., horse vs. dog).
- Wipe-on Solutions: Many fly sprays are designed to be wiped on rather than sprayed, which is less stressful for skittish animals.
Trapping Methods: Reducing the Local Population
Using traps helps lower the overall population of flies in your yard or pasture. This contributes significantly to overall outdoor fly control.
How Effective Are Fly Traps?
The fly trap effectiveness varies greatly depending on the type of trap and the intensity of the local fly problem. Some traps are better for house flies, while others target biting flies specifically.
Sticky Traps and Sticky Surfaces
These traps use a large, sticky surface coated with an adhesive.
- Horse Fly Bags (Biting Fly Traps): These specialized traps are highly effective against horse flies and deer flies. They mimic a host animal using a dark, round object (like a large black ball) suspended over a wide funnel leading to a collection container. Flies are attracted to the dark sphere, mistake it for a body, and fly up into the trap.
- Drawbacks: They require proper placement—usually in direct sunlight near where flies congregate.
Water Traps
Some traps use water mixed with attractants. Biting flies land on the water surface or are drawn by CO2 sources, then become trapped or drown.
The Role of CO2 Traps
Advanced biting fly control often involves CO2 traps. These machines release a plume of carbon dioxide, often mixed with an attractant lure (like octenol), mimicking a large mammal.
- Pros: They can capture thousands of flies over a large area.
- Cons: They are expensive to purchase and operate (due to propane or CO2 tank refills). They are often best suited for large properties or farms.
Environmental Management: Stopping Them at the Source
Controlling where flies breed is fundamental to long-term success. Horse flies and deer flies have specific life cycles that we can disrupt.
Managing Breeding Habitats
Deer flies often breed near moist, shaded areas, like stream banks or wooded edges. Horse flies prefer muddy areas or manure piles.
- Drain Standing Water: Remove any standing water near your home or activity areas. While the larvae don’t develop in deep water, wet, muddy soil is crucial for their pupation stage.
- Manure Management: For farms, promptly remove and compost manure. The less accessible manure and decaying organic matter, the fewer flies can complete their life cycle.
- Keep Grass Short: Biting flies rest in tall grass and brush during the hottest parts of the day. Keeping lawns mowed reduces their resting spots near activity zones.
Using Beneficial Insects
Natural predators can help keep fly populations in check, though this is a slower method of outdoor fly control.
- Ground Beetles: These predators eat fly pupae in the soil.
- Parasitic Wasps: Certain wasps lay eggs inside fly pupae, killing them before they hatch. Introducing these should be done carefully, often by purchasing cultured colonies for release.
Specific Strategies for Deer Flies vs. Horse Flies
While general methods work for both, focusing on the specific habits of each fly can increase your success.
Targeting Deer Flies
Deer flies are generally more active in the morning and early afternoon. They are often found near woodland edges and fields where they hunt.
- Focus on Movement: Since they react strongly to movement, stand still or move slowly when actively hunting for them.
- Use of Blue or Red: Some research suggests deer flies are strongly attracted to specific wavelengths of light, sometimes favoring blues and reds over greens. Wearing minimal bright colors in these shades might make you a target, but using these colors in a trap can draw them away from you.
Targeting Horse Flies
Horse flies are often seen near water sources or large, grazing animals. They tend to attack during the hotter parts of the day.
- Target Large Objects: They are drawn to large, dark objects. If you have livestock, painting large barrels black and placing them near pastures might act as decoys, drawing flies to traps instead of animals. This is a form of decoy-based biting fly control.
- Barn Fans: Using large circulating fans inside barns or shaded resting areas for animals provides excellent deterrents.
Treating Biting Fly Bites
Despite the best prevention, you might still end up with a bite. Knowing biting fly bites treatment helps relieve the pain and prevent infection. Remember, because these flies slash the skin, their bites often bleed more than mosquito bites.
Immediate Steps
- Clean the Area: Wash the bite immediately with soap and water. This helps remove any lingering saliva or potential contaminants.
- Stop Bleeding (If Necessary): Apply gentle pressure with a clean cloth if the cut is still bleeding.
- Avoid Scratching: Scratching can introduce bacteria and cause secondary infection.
Relief Measures
- Cold Compress: Apply ice or a cold pack wrapped in a towel for 10–15 minutes. This reduces swelling and pain.
- Topical Creams: Use a topical anti-itch cream containing hydrocortisone or a calamine lotion. Baking soda paste (baking soda mixed with a little water) can also soothe itching.
- Antihistamines: If you have a strong reaction or many bites, an over-the-counter oral antihistamine can help manage itching and swelling.
If signs of infection (increased redness, warmth, pus, or fever) appear, seek medical advice.
The Role of Fly Repellent Clothing Technology
Modern textiles are beginning to incorporate fly repellents directly into the fabric. This is an emerging area of fly repellent clothing.
Permethrin Treatments
Permethrin is a synthetic insecticide that repels and kills insects. It is not typically used directly on skin but is highly effective when bonded to clothing.
- Duration: Clothing treated with permethrin remains effective through dozens of wash cycles.
- Safety Note: Permethrin products are generally safe for humans when applied correctly to fabric, but they are toxic to cats. Treat clothing outdoors and allow it to dry completely before wearing or allowing pets near it.
This method offers long-lasting protection compared to reapplying a deer fly spray every hour.
Analyzing Commercial Solutions for Biting Fly Control
When seeking the most potent solution, commercial products designed specifically for these tough flies are often superior to general bug sprays.
Specialized Deer Fly Sprays
Look for sprays marketed specifically for horse flies or deer flies. These often contain higher concentrations of active ingredients or use synergists that boost the repellent power. They are usually designed to be safe for use on clothing as well as skin, offering dual use as a deer fly spray.
Lures and Baits
Some products work by attracting the flies to a specific spot and then killing them chemically or trapping them. These are valuable components of a comprehensive biting fly control plan, especially around barns or pool areas where outdoor activity is high. Ensure any bait or chemical used is safe for the environment and any domestic animals nearby.
Maintaining Effectiveness: Consistency in Application
One of the biggest failures in fly control is inconsistency. A product only works when it is applied correctly and reapplied when necessary.
Reapplication Schedules
- Synthetic Sprays: Follow the label. Usually, every 4–8 hours unless sweating heavily.
- Natural Insect Repellent: Essential oils for biting flies evaporate quickly. Reapply every 45–60 minutes, or immediately if you start noticing flies landing frequently.
- Traps: Check and empty traps regularly. A full trap stops working.
Keeping Gear Ready
Keep your fly repellent clothing treated or accessible. If you know you are heading to a known high-fly area (like near a marsh in July), put on your protective clothing before you leave the house. Don’t wait until the first fly buzzes your ear.
Summary of Best Practices for Outdoor Fly Control
Achieving peace from these biting pests requires a layered defense system. Think of it as concentric rings of protection around yourself and your property.
| Defense Layer | Examples | Primary Goal |
|---|---|---|
| Primary Exclusion | Screens, Clothing, Fans | Stop contact entirely. |
| Topical Repellents | DEET, Picaridin, Essential oils for biting flies | Deter landing on the body. |
| Area Reduction | CO2 Traps, Sticky Bags | Lower local population density. |
| Habitat Modification | Mowing, Draining Water | Remove breeding and resting sites. |
By combining physical barriers with effective repellents like a good deer fly spray and consistent maintenance of traps, you create the most hostile environment possible for deer flies and horse flies.
Frequently Asked Questions (FAQ)
Can I use dog flea and tick repellent on myself to repel horse flies?
No, you should not use most dog flea and tick products on yourself. These often contain permethrin or other chemicals designed for animal coats, and their safety profile for human skin is not established or may be unsafe. Stick to products labeled for human use or use dedicated natural insect repellent options.
Are essential oils strong enough to be effective horse fly deterrents?
Yes, certain essential oils for biting flies, particularly oil of lemon eucalyptus (OLE) and geranium oil, can provide short-term protection comparable to lower concentrations of DEET. However, they require much more frequent reapplication than synthetic sprays.
How long does treated fly repellent clothing last?
If the clothing is professionally treated (like high-end hunting gear) or treated with a product like permethrin spray, the protection can last for several weeks or many washes. A simple spray of a deer fly spray onto fabric will only last until the first rain or heavy sweat, though.
Why do horse flies keep attacking me even after I spray myself?
This often happens for a few reasons: 1) You might be sweating heavily, washing the repellent off; 2) You haven’t reapplied the repellent recently (especially true for natural products); or 3) The product you used is more effective against mosquitoes than these larger, more aggressive biting flies. Ensure you are using a product marketed for general biting fly control.
Is it true that flies are attracted to blue or black cars?
Yes. Horse flies, in particular, are very attracted to large, dark, moving objects, which they mistake for large grazing animals. This is why many fly trap effectiveness designs use large black spheres as decoys.