cows in field

Kevin Jahnke Fly Trap

Added February 3, 2011. The trap is constructed from a used 55 gallon plastic barrel. The top is opened and fitted with a clear plastic window (approximately 8" x 10"). Four – 2" PVC pipe elbows are mounted facing downward (and in) about 2/3 of the way up from the bottom of the barrel on the inside. The elbows are extended downward with a 4" piece of PVC pipe and mounted at 90 degree intervals around the barrel. Add 8-10" of water to the barrel and put in some liquid dish soap to decrease the surface tension on the water. Add some decaying food material as bait to start the trap. Once a good number of flies start getting caught it will no longer require bait as the dead flies serve that purpose. Maintain the traps by opening the top and scooping out the dead flies every week to 10 days. Place the traps where cattle congregate – water tanks, lane intersections, etc.

Flies enter the trap through the side openings (PVC elbows) when they smell the bait.

Once inside the trap, flies try to escape through the clear window on top but since they can't get out that way they eventually fatigue, drop into the water and drown.

Kevin Jahnke is an organic dairy farmer and CROPP cooperative member that farms near Lancaster in SW Wisconsin.