I just noticed the same on my native king orchid. Might have a go at
wrapping the stalk in gauze or similar.
Jock
"Richard Wright" wrote in message
...
Something eats the stems of my rock orchids (Dendrobium speciosum) in
my Sydney garden.

What happens is that the outer sheath of the flowering stem is eaten
off, so the whole flowering spray withers.

I have never caught anything at it, but I suspect snails or slugs.

My neighbour never gets the problem. I get it every year.

Any suggestions about the culprit?