Fruit that I anticipate all year has begun to come into season, and resides in the fruit bowl. Usually it is rapidly eaten, but sometimes we are plagued by fruit flies. One year the flies were particularly, er, fruitful, and we had them clear through November! Somehow they took up residence on our bathroom mirror. This initiated some research and testing, and the resulting fruit fly trap.
Begin with a jar. We like glass so we can watch the proceedings.
Curl a piece of paper over on itself to form a cone with an opening at the point roughly wide enough for a fruit fly and one or two of its closest friends to slip through. Set the cone into the jar point down, shuffling the shape until the point reaches about half way down and the edge meets the glass. Tape the edge of the curled paper shut to keep the cone in place. Close any gaps to prevent any marauding fruit flies from escaping along the edge.
Slice the paper across at a couple of centimetres above the edge of the jar.
Cut tabs around the top edge to allow folding.
Ready? Toss in something your fruit flies have been enjoying. Mine are particularly fond of overripe fruit, wine, a touch of vinegar added to help things along if you like. I had a few leftover blueberries on hand, and a splash of red wine.
Fold down and tape shut the top edge of the cone to the glass. Set the jar in fruit fly territory.
Observe. The flies find their way in, yet cannot find their way out. No, it isn’t friendly. They die. They don’t live particularly long anyway, you’re just giving them a sweet place to live out their lives. I catch and release spiders, wood bugs, mice, I can accept living with ladybirds and lacewings. Fruit flies, not so much.
Don’t forget to toss the contents before the science project gets out of control! In fact, if you add some vinegar, you’d really just be making blueberry vinegar, which might have been quite nice without the flies in it.