hlepful decription
KISS - keep it simple .....
1.5 or 2 litre water bottle, cut top off at the neck. Invert said cut off top into rest of bottle. Tape together with ducktape. Punch 2 holes on top for string to hang it up. Put a dessert spoon of jam 2 teaspoons of vinegar and about 200 - 300ml water. Stir a little. Hang out near hive. Cost - very little.
I have four of these around my hive (within 1 metre) and they are full of moths, hornets and wasps. Oh and no bees in there. My bees are free(ish) of trouble. I had no idea of the size of a hornet compared to a bee until I started keeping bees this year!
Hope this helps