We have a simply amazing population of deer flies here at the house. When I pull into the driveway and park, I couldn't even begin to count the deer flies attacking the jeep. It sounds like it's raining on the soft top. I let them settle down before I get out and dash for the house. From what I've read no spraying program is effective enough to be practical in controlling them. A lot of people swear by tanglefoot, which is a sticky material that you spread on a upside down bucket or pot on a stick and either walk around with it held higher than your head or mount it on a vehicle and slowly drive back and forth for a while. They call it trolling for deer flies.
Trolling Deer Fly Trap .
I'm going to give this a try.
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