Do Horse Flies Bite? Discover the Truth About These Pesky Insects

Horse flies and deer flies are a common nuisance for both humans and animals, particularly during the warmer months. These insects are known for their persistent and painful bites, which can affect animals like horses, cattle, and deer as well as people.

Female horse flies and deer flies are the ones responsible for inflicting these bites, as they require a blood meal for egg development. They may target any area of the body, but deer flies typically bite around the head and neck, while horse flies often go for the legs source. Though horse flies and deer flies are notorious for bothering horses, they have a wide host range, attacking various mammals and even sometimes birds and reptiles source.

It’s crucial to protect yourself and your animals from these painful bites, not only for comfort but also because they can transmit diseases. Taking preventative measures can make a world of difference. Horse and deer flies can be deterred, for instance, with proper use of repellent source.

Understanding Horse Flies

Physical Appearance

Horse flies are moderate to large-sized flies, measuring around 14 to 19 mm in length. They have a grayish-brown thorax and clear wings. These flies also have distinctive large eyes that can be brightly colored. Deer flies, on the other hand, are smaller ranging from 10 to 13 mm in length, with greenish-yellow thoraxes, dark-striped patterns, and smoky gray-brown tinted wings source.

Habitat and Distribution

Horse flies are primarily found in North America, where they thrive in damp, marshy areas or near bodies of water. They prefer warm and humid environments. This is why you’ll often find them around pastures or wooded edges, as well as other damp or lush areas source.

Tabanidae Family

Horse flies and deer flies belong to the Tabanidae family of insects. These bloodsucking flies are known for being a nuisance to humans, cattle, and horses. While some species of horse flies may feed on humans in Indiana, deer flies are more likely to do so. They feed on a wide range of hosts, including mammals, birds, and reptiles source.

Key Differences Between Horse Flies and Deer Flies:

Some Traits They Share:

• Both are bloodsucking insects.
• Can be a nuisance to humans and animals.
• Belong to the Tabanidae family of insects.

Horse Fly Bites

How They Bite

Horse flies have sharp mouthparts designed for cutting through flesh, allowing them to extract blood from their host. Female deer flies especially are known to feed on various mammals, with some species even targeting reptiles and humans. They usually bite on the host’s head and shoulders while it moves.

Pain and Symptoms

When a horse fly bites, it can cause significant pain and discomfort. Common symptoms following a bite include:

• Intense pain due to sharp mouthparts
• Swelling and inflammation around the bite area
• Redness surrounding the wound
• A potential rash

Some individuals may also experience more severe reactions to horse fly bites, such as dizziness, difficulty breathing, and wheezing. These symptoms should be taken seriously and warrant professional medical attention.

Infected Horsefly Bites

Although horse fly bites are generally not life-threatening, they can lead to infection in some cases. Watch out for these signs of infection:

• Increased pain or swelling at the bite site
• Redness that expands beyond the bite area
• Pus or discharge from the wound
• Fever

If you notice any of these signs, it’s essential to seek medical help.

Preventing and Treating Horse Fly Bites

Protection for Humans and Pets

To protect against horse fly bites, apply insect repellent containing DEET on your skin and clothing. Examples of such repellents include:

• Off! Deep Woods
• Cutter Backwoods

For pets, use vet-approved insect repellent products.

Protection for Horses and Livestock

Protecting horses and livestock from horse fly bites is essential. Consider:

1. Fly sheets with zebra stripes – proven to reduce horse and deer fly bites.
2. Insect repellent – full-body application of synthetic pyrethroids provides full-coverage protection.

Comparison table:

Treatment Options

If bitten:

1. Clean the bite area with soap and water to reduce infection risk.
2. Apply antibiotic ointment for further protection.
3. Use an ice pack to reduce swelling.
4. Seek medical attention if the bite worsens, causes excessive pain, or swelling does not subside.

In summary, it is crucial to protect humans, pets, horses, and livestock from horse fly bites. Using DEET-based repellents and zebra-striped fly sheets effectively minimize bites, and treatment options like cleaning, applying antibiotic ointment, and using ice packs help manage pain and swelling.

Horse Flies and Disease

Equine Infectious Anemia (EIA)

Equine Infectious Anemia, also known as swamp fever, is a viral disease affecting horses. It is transmitted by blood-sucking insects such as horse flies. Some symptoms of EIA include:

• Fever
• Depression
• Weight loss
• Anemia
• Swelling in the lower abdomen and legs

Tularemia

Tularemia, a bacterial infection, can also be transmitted through horse fly bites. Some symptoms of tularemia in horses include:

• High fever
• Swollen lymph nodes
• Decreased appetite
• Nasal discharge

Comparison Table

Prevention Methods

• Use insect repellents and fly sheets to protect horses from horse fly bites
• Remove standing water and control moist areas to reduce horse fly breeding habitats
• Keep horses indoors during peak fly activity times

Pros & Cons of Prevention Methods

Insect Repellents & Fly Sheets

• Pros: Can effectively deter horse flies, provide physical barrier
• Cons: May require regular application, some horses may be sensitive to repellents

Removing Standing Water & Controlling Moist Areas

• Pros: Reduces breeding habitats for horse flies, helps control other insects too
• Cons: May not be practical for large areas, requires constant monitoring

Keeping Horses Indoors During Peak Fly Activity Times

• Pros: Provides protection, reduces horse stress
• Cons: Limited outdoor time, may not be possible for all horse owners

Managing Horse Fly Populations

Repellents and Traps

Horse flies are notorious for their painful bites, and using repellents can help keep them away from your horses and their living areas. Applying a repellent specifically designed for horses can help deter horse flies from biting. A popular method for capturing these pests is using fly traps designed for outdoor areas, such as stables and yards. Examples of effective traps include:

• Sticky traps
• Biting fly traps
• Solar-powered traps

Environmental Control

Managing the environment effectively can play a crucial role in minimizing horse fly populations. These insects thrive in moist environments, such as marshes and swamps. To reduce their habitat, you should:

• Remove standing water sources
• Maintain proper drainage in yards and stable areas

Another method to protect horses is to turn them out at night, as horse and deer flies are daytime biters. Providing shelters or canopy trees far from wooded edges can also aid in protection.

Professional Help

Sometimes, horse fly infestations are beyond personal abatement efforts and require professional help. An exterminator with experience in horse fly control can assess the situation, identify the breeding sites, and recommend the best course of action for getting rid of the pests. They may use a combination of traps, screens, repellents, and other techniques to manage the infestation.

Remember that managing horse fly populations requires consistent efforts and a combination of methods to achieve the best results.