Glass Wasp Catcher

I bought the wasp catcher not very confident that it would work - however last year my daughters' cat swallowed a wasp and spent a day at the vets so I needed something. I put jam and water in the catcher at first and nothing happened - I then trickled runny honey round the side and used Cloudy Apple juice for the centre - since then I have had very few wasps in my garden and the wasp catcher is full of them. If you fill use fragrant sweet smelling liquid in the bottom then the wasps love it.