[Tattyanne456]

Does anyone know the area that these traps cover? Do I need to get one for each tree, or does one work over a largish  area?

[Trillium]

I believe trap areas are specific to the manufacturer. Some studies I've read say that most pheromone traps are only about 50-60% effective, and tend to attract more pests than originally present. So it's double-ended gun.

What specific pests are you trying to control? 

[Tattyanne456]

Lol Oh dear! You'll think I'm mad, but I'm not sure, I just thought it would be a good idea to get a couple, last year I had trouble with wasps eating into my apples. What could I do about that?

[Trillium]

Specific wasp catching jars are now available and if you can find smaller versions, hang those from apple tree branches and you should get much less wasp damage. Failing smaller versions, then place 1 or 2 (or more) larger versions, depending on your tree size, on opposite sides of each tree.

I've also seen actual store bought apples hung with cord and covered with a special commercial sticky compound called Tanglefoot over here. I'm sure something very similar is available in the UK. You'd have to replace the rotting apple every few weeks but its a small price to pay to minimize the crop damage. The store apple would seem a very early bonus to the wasps, already soft and fragrant, and  they'd adhere to the compound. 

[Ice]

Is it definately wasps or could it be codling moth?

[Tattyanne456]

Thanks Trillium, I'm ashamed to say I didn't think of that, and it is so obvious! duh, if I had a brain... do you think a home made one would work, jamjar filled with sugar water and hung in the tree?
Ice, I'm fairly sure it was wasps, but I'm getting some codling moth traps too.

[Trillium]

The apple covered with tanglefoot is excellent for catching coddling moths, and the sooner they're up, the better.

Wasps can be caught by something like this:

http://www.buzzle.com/articles/homemade-wasp-traps-how-to-make-your-own-wasp-trap.html

or this:

http://www.bbc.co.uk/dna/h2g2/A225839

Just remember the inside the base of the container needs to have a hump, sort of like wine bottle interiors.

[Tattyanne456]

Very useful Trillium, thankyou.