Female horse fly is attracted to hot black ball on our horse fly trap.

Phone camera showing how horse flies hone onto our horse fly trap by infrared signature.  Nature is instrumental in the design of the horse fly traps from Bite-Lite®.

Female horse flies need to find blood in order to fertilize their eggs and reproduce.  Based on what we know about how horse flies find their blood source — by contrast, heat sensory, and scent — the Bite-Lite® horse fly traps exploit the natural tendencies of the female horse fly to trick it into finding our traps and getting caught. 

By placing our horse fly traps in strategically sunny locations, the inflatable black ball will absorb heat, thus putting off an infrared signature to attract the biting female horse fly to the ball rather than to the animals and humans nearby.    Once positioned on the black ball, the females will try to bite their “victim” and after failing, they will follow their usual flight pattern, which is vertical.   The green plastic conical hood guides horse flies into a centrally placed plastic collection bin, which from there they cannot escape.   

Optimizing Your Horse Fly CatchUV proof collection bin on our horse fly trap.

Whether you are protecting a residential or commercial area from horse flies, also known as greenheads, deer flies, yellow flies, and B-52 bombers, there are several ways to optimize the effectiveness of each horse fly trap in order that the female horse flies find the horse fly trap rather than bite humans and animals.

First, determine how many horse fly traps you will need for best efficacy by calculating acreage and square footage.   Based on testing, the best range for trapping the female horse fly with our professional horse fly traps is a five horse paddock or about 2.5 acres.  

The key to nature taking its course is to next identify the likely flight path that horse flies are taking on to your property to reach your animals or you.   Typically, eggs are laid on stones or vegetation right next to a water source.   The larvae will hatch and fall into nearby water bodies or onto moist earth, where they will feed on invertebrates such as snails, earthworms, and other insects.   Adults will emerge from damp areas such as ponds, riverbanks, swamps, fresh water and salt water marshes, moist forest soils, or soft decayed wood after going through a life cycle of six to 13 stages of development, depending on the species.  This cycle could take from one to three years.   Horse flies live only a few days as adults, but immediately begin mating (in flight) and locating blood sources for the reproductive cycle to begin again.   One female horse fly can lay up to 100 to 800 eggs.   Male horse flies don’t have the mandibles to bite, and instead feed on nectar and pollen, and not blood.

Horse fly (horsefly) which is also known as a B52, green head, deer fly, and yellow fly.  For best efficacy, set your horse fly trap(s) just before the first adult horse flies emerge in your area.   On the East Coast, this would be around May.  In warmer climates, you should set the horse fly traps out sooner.   Adult horse flies will usually be seen around late spring and early summer.

Position your horse fly trap close to where humans and animals congregate.   If you are protecting animals, we do not  recommend that you place a horse fly trap inside a paddock or cattle yard, where the animal could brush up against the trap and be hurt or get spooked, or even damage the horse fly trap.   Instead, anchor your horse fly trap just outside a protected perimeter such as a fence nearby.

If you are not catching significant numbers of horse flies, and you are certain the adults have emerged, reposition your horse fly trap(s).

For more details about our horse fly traps, visit our About page.

To see our horse fly trap studies or to purchase our horse fly traps, visit our horse fly trap Order page.