Apples Under Attack...

My Apple tree (hopefully soon to be an Espalier) is under attack! I noticed a couple of leaves were skeletal,  nothing left but the main veins, on closed inspection I noticed lots of little green caterpillar's busily munching away many of the appearing to hang by their jaws only - quite an impressive feat really.

Rather than squish them all or use a pesticide I detached the leaves which where a lost cause anyway and discarded to a wild bit of the garden where they can take their chances but will probably just become part of the food chain, on checking the rest of the tree I couldn't see anything resembling eggs so I'm hoping that's the last of them.

Leafroller Catapillars?

I've been trying to identify exactly what they are, lots of Google image searching for Green Caterpillar with Black Head on Apple Tree Leaf hasn't managed to confirm, I initially thought they were Leafroller Caterpillar's - that said I couldn't find any evidence of leaf rolling, might be they are too young, and the heads seem to be darker plus these have a row of black dot's down each side - can anyone confirm what these are?

An Espalier Apple Tree to be?

I have a small space in the garden that's currently under utilised, a small fence area that gets sun from late morning to mid evening, I initially thought I'd put another raised bed border into this slot but have recently been reading up on growing fruit tress against a fence or wall - I've now learnt that this technique is known as Espalier.

Spare Space

Above is the space I have in mind, what do you think - is this a suitable space? I believe I could eventually get 3 to 4 levels growing up this space providing a good source of fruit, unfortunately there's not enough space to plant a free standing tree which I believe would provide higher yields.

The tree I have in mind to go here is one provided by a relative who has a fantastic house/garden out in the countryside and suffers from tree's sprouting left, right and centre - when I found out I offered to take as many as they wanted, in the main to feed my fascination with Bonsai - more on this in a later post.

Apple (Hopefully)

I believe the tree above to be an Apple tree following Googling of Apple leaves but I can't be certain, any tips on how to positively ID this would be very helpful. I'm hoping that if it grows well this year I'll be able to plant out next year although currently unsure if I need to prepare the tree at this stage to get it ready for it's role as an Espalier - I'll keep you posted on this Journey of discovery!