Hi, I'm hoping someone can help me figure out what's going on. About ten days ago I had a minor mealybug infestation which was treated promptly and successfully with alcohol followed by systemic imidacloprid. At the same time, I found these lesions on the lapidaria margaretae. They do not rub off with firm pressure, damp cotton swab, or firm pressure with a cotton swab soaked in 90% isopropyl. The epidermis must be scraped away to remove *any* of this.
Under a loupe, the lesions have a bumpy/powdery surface, irregular tan margins, and each individual spot has 1-2 small tan bumps that can be felt; scraping one off is what left the pit seen in the photo.
They continue to grow in size and number, and now I'm seeing tiny tan spots on a few other succulents nearby, so I sprayed everything with alcohol and quarantined them all separately.
I have spent hours researching and can find nothing that precisely matches this description *and* which is listed as a disease of succulents. I'm hoping someone here with more experience might recognize this and clue me in, because it's driving me crazy!
Thank you so much for your help.
