A homemade design, unlikely to have been seen before.
The procedure is straight forward once set up. It provides an easy way to obtain environmental data, that over time can be interpreted to provide insight into ecological changes. Other creatures also get trapped.
Moths are thought to navigate by flying at some angle from the line in the direction of the moon. They mistake the light for the moon, and as they get nearer to the light, they thus get into a tight spiral round it that leads them to collide with some vanes stuck to the funnel. They fall in and seek shelter in the egg box compartments.
The standard book, Moths of the British Isles will cost more than the trap. It is by Bernard Skinner. It is quite good with photos and some background information, but I would prefer the photos to be taken in lifelike positions, as opposed to the ones of moths set with pins through them! It is published by Penguin.
I started the trap in August 1997, and caught about 25 species, sometimes 45 individuals per night, in what must be one of the least favourable urban gardens possible.
Mains electricity is used here, so go to trouble to waterproof the electrics. I can of course accept no liability for any misadventure or problems resulting from this design.