By Kish Woolmore
How to make a cheap low-cost Moth Trap:
Generally retail price for readymade moth traps relatively expensive, starting around £150 with good ones being several hundred pounds. Most commercial ones relying on mains power or heavy batteries and not always easy to transport to sites.
Being inspired by a Trap which Katie Boyles from Warren Farm Nature reserve is trying out I decided must be easy enough to make from readily available items with only a limited amount of construction required.
Most of the parts required can easily be purchased from online suppliés like Amazon or Ebay and in some cases may even be sourced from local skips or back of the shed….. Using LED lighting means the unit isn’t as bright and intrusive as the commercial units and thus makes them more suitable for use in urban gardens without causing a disturbance to the neighbours.
What is required a container to trap the moths in and a suitable light source and power supply.
For the container I used a 30litre bucket with lid (I am also going to try a smaller bucket that fat balls come in), for entry into the container I used 20cm dia funnel with the end cut off giving a 60mm hole. Then cut a hole in the bucket lid to fit the funnel snuggly (probably needs a bit of skill to get it good fit and may be easier with specialist compass cutter tool).
For the Light I got a UV LED Strip, these come in various lengths and take some searching especially if you don’t want to wait for delivery from China (where most seem to come from). This is fixed in a spiral around a piece of 32mm Dia plastic pipe. They normally come adhesive tape. You can get 12V or 5V versions, with 5v they usually come with USB plug on the end suitable for directly connecting to mobile phone power pack. The 12 volt version you will need an adapter cable (easy to get online) to step USB voltage up from 5V to 12V. The light unit has to be suspended over the Funnel, there are various different ways this could be achieved but the simplest require least amount of messing around was to get a plumbing fitting (Bulkhead connector) size to match the pipe used and fit this to the frame of a lampshade. It can then stand freely over the top of the funnel, the lamp shade used should be large enough. If you can’t find an old lampshade there are online suppliers that you can get lampshade making frame kit (some even sell just the lamp holder frame).
I already had USB Phone power pack so just needed to put the parts together and plug in. The total cost using new components (excluding the power pack) was around £35.
Note the LED strips are available with silicon covering to make the splash/water proof… But online articles suggest the silicon deteriorates and they aren’t as effective as the non waterproofed versions.
I used a 5v LED strip which I think isn’t as bright as the 12V ones Katie had, so I intend to try a 12V one later and compare for effectiveness.
Unlike many commercially available traps this one doesn’t have any light baffles (not sure if these affect the performance or just to assist in mounting the light), these would need to be custom made from plastic, so something to try at a later date depending on success I get without them.
Another possible consideration is some form of shield to protect from rain. The ones Katie is trying out have Light Switch so they automatically turn off when it gets light, but I considered this wouldn’t be necessary for where and when I am likely to use mine.