Biting Fly Trap

Late last summer, the greenheads and horseflies here were horrible. The horses didn't even want to be outside in daylight. There are some fancy horselfy traps available for sale, but they are shockingly expensive. I found plans for an easy and cheap DIY biting fly trap here. Here is what it looks like with a 24" beach ball, spray-painted black, as bait:

I put the trap out again for the year not even five days ago and it's filling up!

I've found it does catch a lot more greenheads than horseflies, but every single dead biting fly is a victory. Totally worth the few dollars I spent on materials.

A friend who horse-sat for me did make a funny comment, that my horseflies seem smarter than hers at home. This made me a little worried that my trap plus natural selection will cause the evolution of a super-intelligent population of horseflies. Eek!