What's eating my plaid cactus?

Plaid Cactus (Gymnocalycium stenopleurum 'Friedrichii') is a prized collectible houseplant whose distinctive patterned skin can mask early pest damage. Mealybugs are the chief threat, nesting in the ribs. Spider mites cause subtle stippling that may be mistaken for natural variegation. Scale insects also occur. Close inspection under magnification is recommended for high-value specimens.

White wax in rib grooves, slowed growth, faint yellowing of the patterned skin Isopropyl alcohol swabs precisely applied in furrows; neem oil spray; isolate from other cacti immediately on detection

Fine stippling on the ribbed surface that can mimic natural color variation; webbing in very dry conditions Neem oil or miticide spray every 5–7 days; increase humidity; check underside of ribs where mites congregate

Small hard bumps on the body, difficult to distinguish from the natural texture without close examination Examine under magnification; remove with toothpick and alcohol swab; apply horticultural oil spray