Garden Pests and Diseases: Cactus disease ID and treatment., 1 by franj

franj wrote:
Hi all,

I bought several of these as investment. It's so rare to see them and they'll fetch a few dollars on Ebay :-). Now I'm worried my investment is all going down the tubes. In the past week or so, several of the plants have developed pinhead to 1/8 inch size brown or black spots. The spots are raised and hard. Strangely, it seems to be mostly on the older growth. Insects, fungus? There's no sign of spider mites or mealy bugs, cacti and succulents worst nemesis. I don't know what to do. I'll be taking cuttings of unaffected growth off all the affected plants. And I've quarantined all of them. Any ideas.

Note; I've also posted this over on the Cacti and Succulents forum.

Dave