Homemade wasp traps
DS told me how to make these out of 2 litre bottles. cut the bottle a third of the way down and invert the top into the bottom. It looks like a funnel inside the bottle. Then punch hoes in the sides in which you will put wire to hang from a branch or crook. I used old pineapple juice in mine. I hope you can get the idea from the photo. Hope this helps. I think you could use the small personal sized water bottles too.
Here is a link that might be useful: