[MLP]

Any advise would be greatly appreciated, I'm not sure what is going on - it started a month ago with a new Cattleya I received from a reputable grower, had it about a month and one of the p-bulbes was BLACK, mushy and fallen over - I assumed it was fungal rot ?? not sure why? if anything I would have said I underwated this one, anyway, cut off the bad, disinfected, repotted and moved on, since then a small noid Cattleya got it on one of her p-bulbs, and now my Psycopsis Mendenhall seems to be getting it! on the Psycopsis, should un-pot/cut off infected pbulb, or just cut away the bad part?? also, how is this spreading?? my plants don't share water, were not in the same location at the same time, I water in the morning and am very careful. I am attempting to attach pictures and hope I am putting my question in the right place?