Herniated buds

[Louis_W]

Ok so i know that stuff like this happens and its no big deal, but ive been noticing a pattern lately.

I have quite a few bifoliate cattleya species and primary hybrids. This year almost every single one (4 plant in a row so far) has had one or two buds with an exposed (herniated) patch like these. Generally its many flowers and somewhere in the middle is an affected bud.

The flowers turn out normally and i usually cant tell once they open, but im just curious if anyone knows what causes this? Heat during development?