Wednesday, 24 May 2017

Home Made Light Trap

It had to happen, it's that time of year when the few winter/spring-flying moth species are over and there's a sudden stampede of new and exciting species on the wing, seemingly more and more with every passing night. The Skye Moths Facebook Group has been teasing and taunting me for weeks now. I've found a few bits n bobs, mostly either microleps by day or the occasional macro beneath security lights by night, but the pace has really ramped up this past week or so with several members posting pics of some amazing moffs that they've trapped. 

Light traps, usually called moth traps (though that's a pretty blinkered phrase to be honest) are by far and away the most effective way of recording the moth species to be found in a given locality. In a nutshell they consist of a collecting box or a collecting bucket, both with a bright bulb used as the attractant. Moths are drawn to the light and end up inside the container, ready for inspection by the trapper. They can then be recorded and released essentially unharmed. It's very popular nowadays. 

Anyway, to buy a Robinson Trap (bucket design), with the electrics, will cost over 400 quid (!) and the Skinner Trap (box design) will set you back over 200 quid. Quite frankly it's preposterous, maybe even racketeering. I'm not sure, I can't chuck that sort of money around either way. But I can't keep on being gripped off by other people's moffs either. I had no choice, I had to make my own trap! 

A sheet of ply, 2 hinges, some 2x4 and a lot of screws later and it was done. My beautiful, beautiful invention

Ready for action!
Flap top lid for easy access - novel idea huh?
Obviously I'll need a few more egg trays but it's a start
Storage shed for when not in use
The light is just a standard bedside lamp with the shade removed. Clearly this isn't the best option for attracting moths or for being weatherproof. I'll make a rainguard next, but ideally I should order a proper bulb with electrics. Chatting to the folks on the Skye Moths FB Group it seems they mostly use 125W MVL, the moth-er's bulb of choice. I last ran a moth trap maybe 20 odd years ago and used this bulb with exceptional results. The problem is that they are dangerous, can explode if they get wet whilst hot and probably leak more radiation than Fukushima does. Hence they are being phased out very soon. Probably no bad thing, truth be told. 

Anyway - my first trapping session in who knows how many years is currently underway. I used to trap with Jim Porter (yes, THE Jim Porter) and we'd open the hatch of his Cavalier, sit in the boot drinking beer whilst he smoked stuff he probably shouldn't have smoked and I demolished whatever crisps and chocolate I could find beneath his seats/in the footwell. Once, at around 1:30am one night in the depths of Epsom Common, we were approached by a gentleman in a business suit and holding a case who asked us what we were doing so far into the woods at night. We amiably explained that we were recording moths and he left us to it. Looking back on that odd encounter, the obvious question should have been what the heck was HE doing in the middle of the woods at 1:30am in the morning, wearing a business suit with case! 

So, trap is built and ready for action. It's a bit misty and mizzly here at the moment. The light is on but the trap is inside the shed, just in case it starts raining later tonight. By all accounts there will be an inch of dead or angry midges in the bottom of the trap at the height of the season and one guy had his bulb fail due to the thread being clogged with their bodies!!!! Holy crap, what have I done? 

My last pre-trap moff image is this one

Micropterix calthella in a buttercup flowerhead
These tiny moths (wingspan of about 10mm) possess jaws, unlike all other families of British lepidoptera which have a proboscis. These bad boys basically stomp around chomping pollen grains from flowerheads rather than gracefully sipping nectar. This time of year they are positively abundant across much of the country, just check a buttercup near you! Larger sedges are also well worth checking. Pendulous Sedge for example, may have 20 or more moths per flowerhead, though it is very localised on Skye (recorded from just 4 tetrads according to the BSBI Maps). So far I've seen the moths on Creeping Buttercup, Lesser Celandine and Marsh Marigold. 

Right, must dash. I've a light trap on the go don't you know...


  1. That looks like the business and and a lot cheaper than the pre-made jobs too.
    Just try not to electrocute yourself before you get the lighting sorted!
    We're all sitting back waiting for those moth photo's to appear now.........

    1. Hope it's a comfy seat...trap was utterly empty this morning. I'll have to alter the lid a bit and make some sort of baffles to guide them in. Next time!

  2. Excellent work. Watching that with interest. However, Paul Batty is the man to talk to for a reasonably priced moth trap or even just electrics -

    1. Nice one, coz clearly the bulb I used isn't the moth magnet I hoped it would be!

    2. p.s. on my early email I think an MV top end from Paul set me back about 60 quid

  3. I have one of his heath traps and when he cooked up an MV upgrade for it I asked him to make me up a whole one as a top end. Now I have two top ends (MV-mains/actinic-battery) for the same bottom end - perfect. All in probably half the price Anglian want for a big plastic bucket

  4. Jim Porter, what a guy and a fantastic moth mentor. I wonder what he's up to these days.

    I don't think I've ever had as much fun hunting moths as I have done in the Hebrides. So many nice under recorded micros to snap up in the sheltered gullies!

    1. Last I heard (from Graham Collins coupla years back) was that he'd jacked it all in and taken up his childhood dream of steam engine trains. Massive loss to the mothing community, entirely on a par with the sudden loss of Johnny Allen. Great to see what you're up to in Dorset, buddy. You do kinda get around! :)