I see you were asking about the wing and not the fuse...yet.
There isnt really a lot to save weight wise in the wing.

You can hollow out the wing tips. They are solid balsa.
Sheeting with 1/16 balsa instead of 3/32 may save a bit
but would make the wing more fragile. If you do that I
would recommend keeping it 3/32 in the center where
you will be handling it most.

I think that most of the weight you are going to be
able to save is going to be in the fuselage.

Best of luck...

Mike Hammer