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Moth Trap Recommendations, Please

I’ve had a couple of Hawk portable (12V) moth traps. The first one was great; the second one has always been a pain and I’m not going to keep on trying to repair it.

Has anyone got any recommendations - positive or negative - for a replacement?

Should I also be considering 240V? Why?

Many thanks.

I was due to attend a Butterfly Conservation Society event in the Holyrood Ranger Centre which was cancelled due to Covid-19. I can’t recall the details but attendees were going to be offered a Moth trap on loan from Lothian Moth Group. It might be worth contacting the group to see if it would be willing to loan you one to try out.

Might depend where you want to use the trap. I think LED light traps are now lighter and easier to use with lithium batteries although cost more than other types and may not have such a high catch rate as some other traps.

It will always be near home or car so weight is not a particular issue (and a heavily used electric wheelchair in the household provides a ready supply of 2nd hand lead-acid batteries!) It is sometimes used away from a mains supply but I have an inverter which could be used if necessary.

I’ve not been impressed by what I’ve heard about catch rates in LED traps, though I’m sure that will change as the technology improves.

One of my reservations re mains units is the possibility of the light disturbing suburban neighbours. I’ve already had the police called when I was using a torch to look for earthworms on the grass at night!

Thanks. I’ve applied to join their FB group.

Really depends on what you are doing. Some questions to ask yourself.

  1. Will you have access to mains or equivalent electricity (e.g. a generator). If not that rules out most/all MV set ups and some of the more powerful (say 60W) actinic rigs.

  2. Will you be trapping where the light will disturb people. If so that rules out the standard ‘white’ MV. You can get an MV black light but be warned they run very hot and can explode if water falls on them so should not be approached when switched on.

  3. Will you be inspecting the trap at dawn/first light, or do you prefer a lie in. Ideally of course you should always do the first but if you cannot a design like a Robinson or Heath which retains moths more easily once they warm up is probably preferable to a Skinner design.

I’ve had some success with UV LED recently using a homemade design (strictly made by a really helpful person from Selborne Society who is skilled with electronics). They have the advantage of the bulb being very light and running on D cell batteries making the rig ultra-portable (although covid-19 lockdown kicked in before I had the chance to ultra-port it anywhere). Key thing there if getting the right sort of LEDs, the seller I found has now run out, but some of the cheap ones you can by on a popular South American river themed websites don’t actually put out UV light, they are just white with a blue filter it seems.

I’ve gone down the DIY route.

I got strips of white and UV 12V LEDs and wound them as a double helix round a plastic bottle.The bottle cap is bolted under the rain guard of the old trap. A direct connection to a 12V battery provides the power. Over time, I’ll experiment with using just the white LEDs or the UVs or both together.

In another bottle, I mounted a 240V 20W actinic Wemlight tube. This doesn’t require a ballast, just a direct connection to the mains. It also mounts to bottle cap under the rain guard.

Initial catches have been encouraging.

Minimal waste. A trap with alternative lights and power sources. What’s not to like?

Sounds interesting, have you checked the temperatures so that nothing is likely to melt?

Not checked, but no signs of heating. There’s nothing about the circuits to suggest to me that there is a risk of overheating: do you think I’m missing something?

It may be fine but all lights do give out some heat and if they are in a confined space then this can build up.

May be interesting to record the catches in each system when running them both at same time.