He/she was concealed under the bark of my dendrobium. It is around 8mm long. I have found one every time I water over the last three waterings... comes to the surface as it doesn't like to be dunked... apparently.
It's not bright Orange like the dendrobium beetles I've seen in other photos.
If it is a roach and they don't like to be dunked, you might want to try and give your affected plants a good dunking to try and get them all to the surface and then collect them and follow Philip's advice in terms of how to "take care of them". Repeating this for a few weeks should help take care of the problem. Good luck!
If you've got pet lizards of any kind that is able to feed on a roach or a pet snake that is an insectivore, feed it to them!
Reptile Amphibian - Blue Tongue Skink
There's a family of blue tongue lizards in the garden. The roach I photographed chewed its way through the plastic wrap I sealed its collection jar with and got away. Stomping on them seems to be most effective.... But I'm going to have to start wearing shoes!! )