Morgan Murphy

Do Zebra Stripes Really Deter Flies?

Let's face it, flies are a real nuisance! When it comes to the summer months, our horses (and us) can become extremely irritated by these flying pests. Flies are also bad news for the health of your horse –if your horse has a wound, flies can attack the tissue and cause infection. Flies carry disease and when they bite or drink from a wound they can pass along allergies such as sweet itch.

Black and white stripes are thought to help deter flies*

At Spalding Labs, we are always interested in the latest news on research and findings in the field of fly deterrence. Recently, there was a rash of speculation that zebra stripes could repel Horse Flies, the King Kong of flying pests. In this article we will look at the validity of this research and the implications for horse owners.

Stripes, Stripes Everywhere:

In a study carried out in Sweden, researchers investigated the Zebra's seemingly natural ability to fend off horse flies more successfully than other mammals. Their research led them to discover that areas of the body featuring more stripes deterred more horse flies. The size of the zebras also made a difference. Thinner Zebras seemed to deter more horse flies than their heavier peers.

The team carried out a test using 3D plastic horses which were painted in different patterns–black, brown, white, and zebra striped and then covered in glue. The study was carried out over 59 days and during that time the amount of flies caught by each 3D plastic horse demonstrated a remarkable variance. The black horse had 562 horse flies stuck to it, the brown had 334, the white had 22, and the zebra model had just 8!

The results led the team to determine that dark colored coats attracted the greatest number of flies, while both light and striped coats attracted the smallest number of flying pests.

The researchers concluded that the reason for this is "light polarization." This refers to the way electric vectors in light waves move within the wave lengths of light visible to flying insects. Horseflies, however, are attracted to certain types of polarization and use this to find food, water and shelter. For example, water reflected light causes horizontal polarization which shows Horseflies where to find water sources. Dark coloring on animals causes strong linear polarization, which leads the flies to food sources where they can suck blood, such as horses and cows. Light colors however cause very weak polarization, and as such, are not attractive to the flies. The research led to the discovery that when dark and light colors are adjacent in a zebra pattern, the polarization signals become distorted and confuse the flies. Bottom line? Using a zebra pattern on fly blankets, fly masks, and even lightweight waterproof blankets could help deter flies from your horse.

It is important to remember that this is just a study of horse flies. There are many other types of flies which will bother horses–you can find out about types of flies on our website and how to identify them. The only sure-fire way to ensure your horse and barn are fly free is to start using Spalding Fly Predators in combination with your fly blanket early in the season, prior to the emergence of adult flies. To effectively get rid of flies, it may be required to use these alongside Spalding Fly traps to catch the visiting adult flies from other barns and Fly repellent while in the field or out riding. For a complete fly free summer, Spalding is here to help!

*Image courtesy of Muhammad Mahdi Karim