Thanks Sam172. We're a bit paranoid about wasps now, as last year my husband was stung on the mouth & was rushed to hospital with a very bad reaction. His lip & tongue swelled up to a massive size! He was even placed on a heart monitor & a drip, which worried me sick! We aways use lots of citrus candles, but the wasps keep coming back. I did spray the inside of our parasol with a citrus spray can & it did help, but I shall try your jam jar method the next time we eat out in the garden. Cheers.