Mercury Vapor vs Actinic (2 Viewers)

[Steve Arlow]

Currently I am borrowing a friends MV 125w trap and I'm having variable success, mostly in retained moths in the trap (I've seen moths go in but were not there in the morning). This I am guessing is down to the layout of the egg cartons within the trap in keeping them from escaping.

I am looking to get my own trap, probably for next year but would like one by September this year and wanted to know what trappers think is better; Mercury Vapour or Actinic.

The most popular traps seem to be Skinner and Robinson whilst from what I've read the skinner retains moths less reliably than Robinson though there seems to be a new Skinner out now. The one I'm borrowing is a home made type of trap; bulb, vaines, hole in lid and funnel into the main box.

There is also the issue of cost, Robinson seems more expensive than Skinner so want to make the most of what I will end up getting.

I apologise if this type of thread has been asked in the past.

many thanks in advance

 

[dantheman]

Whilst you're waiting for the experts to come along ...

I've read that MV brings in up to 50% more moths in terms of number of species, and in overall numbers of moths. However, some species do seem to prefer to come to the wavelength of an actinic.

Other than cost, I think a couple of other criteria are power source; with an actinic you have the possibility of running it off a battery rather than a generator if you want to go wandering off into the countryside, and the brightness may be an issue if you have neighbours close by.

(I've never used MV, just got a 6w Heath, so not speaking from personal experience in a comparison...)

And eggboxes and retaining moths; yes, I believe it is to do with packing them in (in my trap at least), whilst making sure they have suitable gaps between them if you wish to retain a maximum catch.

 

[Brian Stone]

I've recorded 605 species to 125W MV and 372 to 15W Actinic. This is against a background of trapping much more often with the MV. Some of the best stuff has come to the actinic though.

Another factor in deciding on the type of trap is transport and storage. My Skinner packs down flat; great for taking away on holiday, etc.

 

[Pie Face]

I've avoided using MV so as not to upset the neighbours too much. Added to this it takes long enough sorting out the catch from my actinic trap never mind increasing it by 50%.

 

[Andy1979]

Sorry, I'm not one of the experts, but can talk from my use of a Skinner with 125w MV. I bought it from ALS (Anglian Lepidopterist Supplies) and it now has two strips at the point of entry which assist in preventing moths from escaping. I'm sure the Robinson does retain better, but it's really down to cost. The Skinner can be flat-packed and very easily assembled (30 seconds ish) if you are moving it about. I've only ever used 125w MV, so can't comment on the actinic, but would advise calling ALS. They are really helpful and you don't get the feeling they are just 'pushing' the sale.

 

[llendorin]

As stated, it really comes down to preference... if you live in a built up area and neighbours could potentially see the light (and you plan on trapping at home) - Go actinic.

If you live in the middle of nowhere, or plan on trapping away from home - go MV.

Although... in saying that... other things to consider are power options - if you want to trap away from home, you can normally get away with a battery pack for an actinic, but an MV setup will require a generator.
MV bulbs run hot, and have a tendency to break if they get rained on, so there may be an upkeep element involved there, too.

I've used both, and although the actinics don't tend to bring in as many moths, they seem to do just fine (at least for me) in terms of number of species attracted.

 

[antshrike69]

I've only used MV. I run the traps in the garden but I'm lucky in that we are an end house so the light isn't overlooked by other people. I can certainly see MVs causing problems with neighbours if that wasn't the case.

Before I got my traps, my research suggested what others are saying - MV brings in larger numbers but the total diversity is not that much different with an actinic and some moths even prefer those bulbs. However, you can't beat sitting by an MV trap on a warm night and being bombarded with huge numbers of moths! On a good night here, the 2 MV traps bring in 500-600 moths of 100-130 species.

 

[billsbirding]

I can't add anything to the above, but this is a great guide that you should find useful

http://www.bioquip.net/which_moth.pdf

 

[Surreybirder]

"A guide to moth traps and their use" is also worth buying. It's only about £5. It's by Reg Fry and paul Waring (he of the field guide).
I wouldn't argue with any of the above but I've been running an MV (first 80W and now 125W) for about 7 years and have never had a bulb go. I ran an 25W actinic for a while and it has the advantage that you don't need a rain shield. It caught moths but not the number or variety of the MV.
Ken

 

[antshrike69]

And in about 15 months of almost nightly trapping with 1 or 2 MVs, even when raining at times heavily, I've never had a bulb blow either. Let's hope the pouring rain outside doesn't prove me wrong later...

 

[aflickering]

i use a blended mercury bulb plugged into the mains (i've tried 100w and 160w and there doesn't seem to be a significant difference in numbers) and it doesn't get anywhere near as many species, but i don't really have time to be sifting through hundreds so that's a good thing as far as i'm concerned. still got some beauties in there and that's the main thing they do crack in the rain though

 

[Steve Arlow]

many thanks to everyone for the pro's / cons of the light source. I'm using/borrowing an MV for garden use and as mostly surrounded by trees isn't really an issue with annoying neighbors.

Given catch retention I've read that Robinson is far more effective than Skinner but would this be down to trap design or layout of of whats put inside, i.e. egg cartons.

 

[Oleander]

many thanks to everyone for the pro's / cons of the light source. I'm using/borrowing an MV for garden use and as mostly surrounded by trees isn't really an issue with annoying neighbors.

Given catch retention I've read that Robinson is far more effective than Skinner but would this be down to trap design or layout of of whats put inside, i.e. egg cartons.

If you just have something to put in the gap in a Skinner you will not loose many moths. Right now I tuck in a towel there and I that works good.

 

[Surreybirder]

....Skinner but would this be down to trap design or layout of of whats put inside, i.e. egg cartons.

There's more room for moths to escape from a Skinner, but some people ameliorate the problem by attaching flaps to the main sheets of plastic to act as baffles for moths trying to escape. No trap will retain 100% of the moths.
Ken

 

[antshrike69]

It often amazes me how something you personally saw vanish into a trap can be gone by the early hours, however many steps you take to avoid that happening. I had a Maple Prominent the other night settled under the egg boxes in my Robinson trap but there was no sign by the next day. So Ken is right - no matter what trap you get or make, you will lose some moths.

 

[Steve Arlow]

With the borrowed trap I have noted several moths go in and as the sides are transparent I could clearly see them under the egg cartons and looking forward to extracting them in the morning only to find they've disappeared.

The trap is currently on until the morning but usually off just before first light, and before I've risen from my pit, so could it be that with the light suddenly not there anymore they are flying/climbing out as dawn approaches.

The past two catches have shown far more moths on the fence and wall around the trap than actually in it with the most interesting fellers found on the outside. I've tried different variations on positioning of the egg cartons inside to prevent escape but it seems I may have to set my alarm clock an hour or so earlier to plug the hole.

In general what would be considered better at retention, the more expensive Robinson over the Skinner or would the skinner work as well with a bit of DIY to attached cross strips across the gap; how far apart should these be?

Again many thanks for the comments and suggestions and here's hoping to a relatively windless weekend....

 

[Surreybirder]

Hi, Caspo,
I think it's definitely better to get to the trap at first light and then turn the light off. I have recently resorted to having my net handy so that I can attempt to catch anything spectacular that decides to fly straight away - with limited success, it has to be said. It's often worth inspecting the outside of the trap first. I sometimes do that before I turn the light off, but I don't like exposing myself to too much UV.
I've no comparative experience but everything I've read suggests that a Robinson is the best at retaining catches. Having said that, some of the traps on Paul Batty's site, which are much cheaper, claim to be as good as Robinsons at retaining moths. I have no reason to doubt him but I wonder if he's ever tried both?! http://www.pwbelg.clara.net/mercury/full-sets/index.html
My previous trap - a sort of home-made Robinson-type trap did not retain the micros too well as there were a few small gaps around the edges. My present commercial one is much better.
There are threads on Birdforum on how to build a Robinson if you have the DIY skills. Some look most impressive.
As I said earlier, it might be worth considering investing in 'A guide to moth traps and their use'. It's a good read, even if it doesn't make the decision for you. It's the kind of booklet that I find myself re-reading every now and again.
HtH,
Ken

 

[Surreybirder]

Sorry, this is a bit of trivial aside, but I posted this link some years ago and it might amuse you. Just in case you are worried about not retaining enough moths!
Go to:
http://www.entomoafricana.org/engl/defaula.html
then click on 'photo gallery'
and then on 'collecting', then the 'night trap' link, then the top place...
and look at the photos - with not a Robinson or even a Skinner in sight!
Ken

 

[Oleander]

It's often worth inspecting the outside of the trap first. I sometimes do that before I turn the light off, but I don't like exposing myself to too much UV.
HtH,
Ken

It is dangerous to be near the trap when it's running? Or is that just with a clear bulb? I usually sit next to my trap for maybe two hours every night :/ I thought that only the bulbs with clear glass was putting out dangerous radiation.

 

[Surreybirder]

Hi, Kalle,
I don't think there's any significant danger in limited amounts of radiation - after all, I visited Belarus within a fairly close distance to Chernobyl when I was writing an article about irradiated food. It's just that I was on some medication that had a warning about avoiding UV radiation.
But I'm happy to say that I'm off that now.
Nothing wrong with topping up your sun tan?
Ken