Although I have had a fair bit of experience with moth traps over the years these have always involved other people’s traps, and usually when I have been leading tours to other parts of the world. Moving to a more isolated location in SE Wales, where we are not overlooked by neighbours, gave me a long-awaited opportunity to buy my own trap and see what we could find. The trap I use is a Robinson trap with a mercury vapour lamp; this lights up most the garden, which is why I was reluctant to experiment when we had nearby neighbours.
Although it’s early days, the results so far have been encouraging. Despite cold nights, March has proved surprisingly productive. My regime is to set the light once a week – any more than this would, I feel, simply encourage the same moths to visit repeatedly, which would prevent them from feeding and mating. Early morning is the time to check the trap, before it is fully light and before the birds have had time to glean any moths that have come to rest on nearby walls and shrubs, and this involves an early start – 5.30am at the moment but this will get earlier as the summer progresses! Species that have been caught previously are released straight away. Anything new is placed in a tub with a piece of tissue and stored away in a cool, dark place (otherwise known as a refrigerator) until I have time to photograph it: photography is the main motivation although interesting records (just one so far) are passed on to the county recorder.
The photography is relative simple. Moths are placed on a background that illustrates their camouflage and photographed with natural light, often using three or four focus stacks to make sure there is front-to-back sharpness. The trick, of course, is to get the stacks done before the moth decides to move off and here a focussing rail speeds up the process as well as making sure the stacks are evenly spaced. Some individuals are then photographed on a plain white background, as records, before being released.
Shown below is just a sample of the moths we have caught this month.
All released moths are taken to a part of the garden with plenty of cover, away from the house, and tipped out into a place where they can crawl down into cover.
Many of the species we have caught are quite plain superficially, but a look through a macro lens, with good lighting, brings out the subtle colours and markings, and definitely enhances the appreciation of these modest little insects.