Urban UV (1 Viewer)

I want to run a moth trap in the shared courtyard outside my ground floor flat. There's a nice dry overhang I can use but I don't want to dazzle the neighbours nor attract too much attention from passers-by.

My main concern is how black is "black light". And how does the visible light vary with wattage? I don't want my porch looking like a dance floor! And are low wattage black lights worth the effort in terms of catch?

Not being a DIY sort, I'd go for an off-the-peg trap. From UK suppliers, I'd be looking at something like a battery 6W 12V black actinic.

Hi Alastair
I've only ever used a 125w blacklight and it produces little visible light - you can just see the element glowing, but it really affects your eyes. It's generally true to say that a blacklight will attract fewer moths than an ordinary actinic. There are also two types of blacklight - the so-called "blacklight-blue" (as used in insectocuters, discos and banks (for checking notes) are not very good at attracting moths.
Running a trap in a courtyard means that you will have to pull in the moths from some distance, had you considered a bigger wattage as I don't think 6w will be very effective. You might have to go to a 15w. The other alternative could be a WEM light, such as the one illustrated here http://www.pestcontrolsupplies.co.uk/wemlite-standard-20-watt-uv-lamp-screw-type-7inch Some people have found them very effective - but you would need mains electric or an expernal light socket.
Whichever sort you decide on I'm sure you will get some moths. Most of my trapping is done here in London and it often turns up some quite unexpected things - even migrant species and species new to Britain!
Best wishes
Martin

Thanks for that Martin. We've been getting a few moth sightings in our courtyard which has a some trees and bushes. My partner has had one migrant moth come to her office stairwell lights and we found a Gypsy Moth in a nearby street. I was hoping a trap would turn up a few more.

I wonder if I'm a bit confused about bulbs and UV. I've seen MV at public moth events and know how super bright they are. How much visible light does a 6W or 15W actinic emit? I'm not sure I've ever seen one in action.

Where abouts was your Gypsy moth. They're fairly frequent in South Kensington and Fulham.
Actinics are mini fluorescent bulbs and as such, don't produce a huge amount of light. 20w WEM bulbs are also mini fluorescents and look like energy-saving bulbs but produce more light than an equivalent tungsten-type bulb.
Martin

I found the Gypsy Moth in the middle of Caledonian Rd N7. I had to wade into the traffic to pick him up! Photo here:
https://www.flickr.com/photos/merula/20494705996/

Back on subject, I think I'll be looking at a 15W Heath trap.