I've seen something similar on one of my figs that I brought outside last year. I thought it was OK because it had been in a very sunny window for a while. But, after I planted it in direct sun, the leaves seemed to almost "burn away" similar to yours. Could this be causing your problem? The fig later recovered but it was clearly not hardened off to the sun yet.

Whispurr
the second picture this one
http://farm4.static.flickr.com/3339/3418904879_cac4924924_o.jpg

look at it as you would a clock dial and focus your eyes at 3 o'clock toward end of that leaf right there at the bottom of leaf is some sort of brownish bug, small beatle perhaps that comes and goes and just might be munching on leaves. I have seen this same type of leave look on my elm tree in certain spots and looks just like yours eats mostly the green leaf and leaves part of the vein ,but i cannot do anything cause its to darn tall. But there must be something you can do i just dont know but something is munching on your leaves and it may or may not be that type of bug i see on that leaf.
Martin

Gypsy moth.

Al

I have seen similarly chewed up vegetables leaves by ear-wigs at night (& gone by the day) and cherry tree leaves by June bugs (but April just started now).

Take a flashlight and go out about 10:00 p.m. and see who's at the party.

Thank you everyone for your replies. As it happened, I read these replies at around 9:45pm so we went out with a flashlight to see who was at the party :) It is indeed ear-wigs. We were shocked. We would probably never have thought to go out at night to check if it hadn't been for the advice. And at least now we know what we'll have to treat the tree for.

Thanks so much, again!

Wonder if tangle foot would work on the earwigs?