How to Get Rid of Horse Flies: Quick and Effective Solutions

Horse flies can be a major nuisance for both humans and animals, especially during the warmer months. These pests not only cause painful bites but can also transmit diseases. In order to protect your property and livestock, it’s essential to implement effective strategies for controlling horse flies.

One method to help reduce the presence of horse flies is to turn horses out at night, as these insects are primarily daytime biters. Providing shelters or canopy trees far from wooded edges of pastures or marshy areas can also offer protection. Additionally, using physical barriers such as fly sheets, masks, and boots can keep the flies from accessing the horse’s face, legs, or body.

Understanding Horse Flies

Species and Identification

Horse flies are part of the Tabanidae family and are known for their large eyes and grey color. There are various species of horse flies, but they all share similar characteristics:

  • Large eyes, often with horizontal stripes
  • Gray or blackish color
  • Moderately large size

For example, common Horse flies are around 14 to 19 mm long, with clear wings and a grayish-brown thorax. On the other hand, Deer flies are smaller, measuring 10 to 13 mm long, and have tinted smokey gray-brown wings, with a greenish-yellow thorax and dark stripes 1.

Life Cycle

Horse flies follow a typical life cycle: egg, larva, pupa, and adult stages. Some notable points in the life cycle include:

  • Female horse flies lay eggs in clusters on leaves or wet soil near water sources
  • Eggs are dark and sometimes covered with a layer of protective, water-repellent material

The larval stage is when horse flies are most aggressive and actively searching for food. The larvae feed on small insects, and some species even feed on slugs, snails, or earthworms. Pupae typically burrow into soil or debris, entering a non-feeding stage before emerging as adults.

Comparison of Horse Flies and Deer Flies:

Feature Horse Flies Deer Flies
Size 14-19 mm 10-13 mm
Wings Clear Tinted
Thorax Grayish-brown Greenish-yellow

In conclusion, understanding horse flies and their characteristics provide a foundation for effective fly control measures.

Horse Fly Bites

Painful Bite Mechanism

Horse flies are known for their painful bites due to their scissor-like jaws. When they bite, they use their mouthparts to:

  • Slice into the skin
  • Create a pool of blood
  • Feed on the blood

These bites can be very uncomfortable and may cause:

  • Pain
  • Swelling
  • Redness

Reactions and Swelling

Reactions to horse fly bites can vary, but common responses include:

  • Localized swelling
  • Intense itching
  • Warmth around the bite area

In some cases, more severe reactions can occur such as:

  • Difficulty breathing
  • Rapid heart rate
  • Nausea

If you experience any severe symptoms, seek medical help immediately. To help reduce swelling and discomfort from a horse fly bite, you can:

  • Apply a cold compress
  • Elevate the affected area
  • Take over-the-counter pain relievers or anti-inflammatory medication

Remember to keep the bite area clean to prevent infection.

Preventing and Controlling Horse Flies

Protecting Livestock

One way to protect livestock, such as horses, is by turning them out at night instead of the day since horse flies are daytime biters. Providing shelters or canopy trees far from wooded edges of pastures or marshy areas also helps protect horses. Some tips to protect livestock:

  • Turn out at night
  • Provide shelter

Keeping Your Yard Clean and Free of Breeding Grounds

Horse flies thrive in damp areas, such as creeks and drainage areas in your lawn. Maintaining a clean yard and keeping long grass trimmed reduces their breeding grounds. Here are some areas to pay attention to:

  • Drainage areas
  • Long grass

Horse Fly Repellents – Chemical and Natural Options

Horse fly repellents can be chemicals or natural alternatives like essential oils. As examples, citronella oil and eucalyptus oil are effective natural repellents, while pyrethrins are used in chemical repellents.

Using screens on windows and doors, as well as sticky traps and disposable fly traps, can help reduce the horse fly population around your home.

Some natural repellents options:

  • Citronella oil
  • Eucalyptus oil

Some chemical repellent options:

  • Pyrethrins
  • Insecticides

Pros and Cons of natural repellents:

Pros Cons
Eco-friendly May be less potent
Non-toxic Frequent reapplication needed

Pros and Cons of chemical repellents:

Pros Cons
Potentially more effective May have environmental impact
Long-lasting Possible toxicity to pets or other animals

Remember, it’s vital to use appropriate methods for controlling horse flies and protecting your livestock, yard, and home. Combining proper yard maintenance with the use of repellents can help you create a safer environment free of painful horse fly bites.

DIY Horse Fly Traps and Solutions

Homemade Mechanical Traps

Homemade mechanical traps are a cost-effective way to control horse flies. An example of this is the umbrella horsefly trap, which can be made using materials like a black pail and a white umbrella. The trap works by attracting horse flies to the dark pail as breeding grounds, and the flies get trapped under the inverted umbrella. Key features of a homemade mechanical trap include:

  • Cost-effective
  • Easily made with readily available materials
  • Targets breeding grounds

Bottle Traps and Sticky Fly Paper

Bottle traps and sticky fly paper are easy-to-make solutions for horse fly control. For instance, a coke bottle trap can be created using a plastic bottle filled with a mixture of rotten meat and water to attract flies. Sticky fly paper placed nearby can catch the attracted flies. Key characteristics of these traps are:

  • Simple to create
  • Easily replaceable
  • Suitable for smaller infestations

Comparison Table

Method Pros Cons
Homemade Mechanical Cost-effective, targets breeding grounds Might require more maintenance
Bottle Traps & Fly Paper Easy to make, replaceable Less effective for larger infestations

Natural Repellent Recipes

Natural repellents can be created using ingredients like dish soap, vinegar, and white vinegar. For example, a repellent spray can be made by combining one cup of water, 1/2 cup of white vinegar, and 1/4 cup of lemon dish soap. Mineral oil and bath oil can also be used as natural horse fly repellents, providing a gentler solution for sensitive horses.

Some advantages of natural repellents include:

  • Chemical-free
  • Safe for sensitive horses
  • Environmentally friendly

Footnotes

  1. Horse Flies and Deer Flies | NC State Extension Publications

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Horse Fly

 

I think its a type of horse fly.
I believe its a type of horse fly it was on my SUV, it was about a inch and a 1/2 long. I’ve never seen a fly this big! You have all the permissions to use the pictures I’ve taken. I sent you a HUGE macro shot, you can resize it if you would like. but I like the details!!!!!!!!
Best Regards,
Mindy

Hi Mindy,
Definitely a Horse Fly in the genus Tabanus, but it will take us additional time to identify the species. Eric’s response is: “The only thing I can say is that it is a female of either Tabanus or Hybomitra. I am so not an authority on tabanids!”

Letter 2 – Horse Fly

 

Subject: Help identifying bug-please?
Location: Michigan
August 6, 2012 7:44 am
Found this guy on my apartment deck. Staring at me. Husband thought it was a cicada, but I’m not sure. It was pretty big-Bigger than my thumb for sure.
Signature: Oddly Fascinated.

Horse Fly

Dear Oddly Fascinated,
This is a Horse Fly and it appears to be a male because of the close set eyes.  See our own Male and Female Horse Fly Eye Comparison.  Only female Horse Flies are Blood Suckers.  We believe the species may be
Tabanus atratus, the Black Horse Fly, based on images posted to BugGuide.

Letter 3 – Horse Fly

 

Subject: A couple curious bugs
Location: Camden, South Carolina
June 26, 2013 6:29 am
Hello! I found the fly outside my work on a window, it had metallic eyes and wasn’t too happy about flash. I was thinking drone fly, but then I started looking up pictures and that didn’t seem right.
The second bug I believe to be some sort of aphid? I found it on my squash, after noticing holes in the leaves. It’s absolutely adorable though with its fluffy little tail. I think I’ll share 😛
Signature: Veronica Roma

Horse Fly
Horse Fly

Hi Veronica,
This is a photo of a very impressive female Horse Fly.  The space between the eyes identifies her as a female.  Female Horse Flies are the blood sucking biters.  Males feed on fruit juices and do not bite.  Your Horse Fly looks like it might be
Tabanus fulvulus based on photos posted to BugGuide.  The other insect looks like an immature Plant Hopper which places it in the same order as Aphids.  Plant Hoppers do not chew holes in leaves, but they do suck fluids from plants and many are considered to be agricultural pests.

Letter 4 – Horse Fly

 

Subject: Horse fly?
Location: NY lower Hudson Valley
July 12, 2013 11:23 am
Hello!
I found this large fly sunning itself on my deck umbrella this afternoon here in NY’s lower Hudson Valley. It’s body is shaped like a horse fly, but it’s markings do not match up with any horse fly pics that I’ve found. It is over an inch long in length. Is it a horse fly?
Signature: Don’t Bite Me

Horse Fly
Horse Fly

This certainly is a Horse Fly, and she does appear to be a female because of the space between her eyes.  Only female Horse Flies bite and feed on mammalian blood.  We believe we have correctly identified your Horse Fly as Tabanus trimaculatus based on photos posted to BugGuide.

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

1 thought on “How to Get Rid of Horse Flies: Quick and Effective Solutions”

  1. hi I was at the beach and a min later I saw lot of flies and when they got closer I started to get scared and then they started to bit I don’t know what
    it was I think it was a female horse flies but they looked super mad I don’t know what it is and I fear it poisons or something worse because I don’t want my family and dog in danger please help me

    Reply

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