Pest or Disease?
 

The symptoms start at the tip of the leaf as a little bit of a lighter green than the rest of the leaf. Gradually and sometimes not so gradually, the tip yellows and it goes down the rest of the leaf but doesn't affect the bulb.

The surface of the leaf is lightly pitted like a tiny insect might have nibbled on it, but it's all over the leaf so I wonder if a tiny insect could do this much damage?

Got any ideas?

Hi DebsC,

It's hard to say what it could be, and I'm not sure if that is a cattleya leaf or maybe a phalaenopsis leaf? You mentioned that it was all over the leaf now. Is it worse looking or did it begin on the underside of the leaf?

One thing I would suggest is to take a white kleenex and rub it along the bottom surface of the leaf. If you get red streaks, you've got a spider mite infestation. I have seen them attack relatively healthy looking phals and other thin leaved plants like catesetums and oncidiums pretty quickly, although I have not seen them on cattleyas or vandas. It's just a thought.

No, this is not a phal leaf but the leaf of a cattleya. I've seen this same thing on my catts and other ones as well as new purchased catts. So it seems to be a quite common problem, I just don't know what the problem is.

I'll do the tissue thing. It can't hurt!

The problem is usually on the top of the leaf but can affect the bottom as well.

Deb, This is what my older catt leaves look like when they are about to drop off. Does you're new growth look like this aswell?

You know, I haven't noticed whether it's just the older leaves or not. Could be. I'll look in the morning and see if I notice this pattern.

Thanks, Gloria!

I agree this is the way my catt leaves go when they are spent . But also check the underside of the leaf for brown circular marks this is usually a fungus which affects the chlorophyl in the leaf