Little-Bee, Where do you live? Based on the sun/shade intensity of your photos, I'm going to say you are probably in the south, or southwest, and your problem is sunburn. The plant appears to be a Phalaenopsis, which are not real fond of strong sunlight, and it looks like you are giving that plant a pretty heavy dose of unshaded sunlight. My .02 cents worth.

BillSC

Also, how long has it been in the tree? Is this its first full year experiencing all of the light conditions in each season or, has it been there for many years with no issues? By the way, i love orchids in trees! i wish i could do more of that.

Meg

Thanks to both of you. Yes I live in So FLA and the Phal is in a tree but sits behind an umbrella so it does not get full sun all day but I would imagine during some times of the day it is exposed more than it should be. I will try moving itl It has been in the tree for about a year maybe a little morel