Thing In The Woods

[Wander]

I've just got back from a stroll around the woods.
Whilst there I noticed something. I saw several of them, about 50 or so yards apart.
These woods are Forestry Commission owned and there's a herd of deer in them. My first thought was that it could be a feeder.
But I don't think it is - there was no feed in any of them and there was no obvious, or easy, way for the deer to get feed out. I can think of simpler and more efficient designs for a deer feeder.
I've no idea what it was. It looked well made and robust, and was clearly put together from pre-existing and purpose designed parts. My instincts tell me it has to be something to do with conservation and surveying, but I've no idea what.
Below are some pictures.
I'd be really grateful if anyone knows what it is and what it's for...

 

[Mesquite]

Looks like it could be a flying insect collector

 

[slowworm]

It's a Cross-vane panel trap.

Actually, like Mesquite says, I thought it was an insect trap, probably a beetle trap of some sort and a quick google finds this:

WitaPrall Cross-vane panel trap

The wet and dry trap for bark beetles, metallic wood-boring beetles and longhorn beetles such as pine sawyer beetles (Monochamus galloprovincialis)…

www.witasek.com

Interestingly, they have similar traps for fungal spores.

 

[Wander]

Yup, that's definitely it.
So would they be trapping them to reduce numbers (best of luck with that) or to find out what beetles are present in the area (and then release them)?

 

[Billy-o]

Bug flies into the black bit, gets a bit stunned and falls into the liquid in the bottom bit.

Re. the blackness: There was a guy that invented a thing for killing tsetse fly. They were busily causing hell among cattle all over Africa, so he tried to figure out a way of attracting flies to a poisoned surface. Turns out a square black sheet looks just like a cow to a tsetse fly, well, all flies. They erected these black sheets on frames all over the place and sprayed them periodically with insecticide and an attractive cow smell. This worked and the moral of the tale is that the domination of the world by insects is going to have to wait until they invent contact lenses.

 

[slowworm]

Yup, that's definitely it.
So would they be trapping them to reduce numbers (best of luck with that) or to find out what beetles are present in the area (and then release them)?

I don't know. They may be trying to see if something has arrived or counting numbers of a pest that's already here. The best way you'd know would be to speak to a FC bod who's there. I assume there's no information on the traps anywhere or by the entrance?

I doubt anything will get released, hopefully the right Pheromone will only attract what they're after.