I have had this cactus for the last year or so. It seemed to be doing just fine, but recently I noticed these white spots at the top of the larger. I have had issues with scale and mealy bugs in the past, but I didn't think this was a result of either. Is this some sort of fungal disease? Will it sp...

Are these brown scale? I tried picking one off. With a little effort, it came off and left a tiny crater underneath. Any ideas?

Hey all. Brand new to the forum and so glad this exists! I've recently caught the cacti bug and have been slowly filling the apartment with plants. Our largest plant is a lovely cereus peruvianus. Recently, I noticed a brown spot midway down the larger stalk (the darkest area within the spot was unf...