What's eating my powder puff cactus?

Powder Puff Cactus (Mammillaria bocasana) is most threatened by mealybugs, which hide under the dense white woolly hair and are hard to spot. Root mealybugs, spider mites, and scale insects also attack indoors. Inspect regularly, especially in the axils between tubercles, and treat early with isopropyl alcohol or neem oil.

White cottony masses tucked under the white hair filaments, yellowing or stunted growth Dab individual clusters with a cotton swab dipped in 70% isopropyl alcohol; for heavy infestations spray with neem oil solution and repeat weekly

Waxy white coating on roots, plant wilts and grows poorly despite adequate watering Unpot, shake off soil, inspect roots, treat with systemic insecticide drench or repot into fresh dry medium after rinsing roots

Fine webbing between spines, faint stippling or rusty scarring on the skin surface Increase humidity slightly, blast with water to dislodge mites, apply miticide or neem oil spray every 5–7 days for 3 cycles

Hard brown or soft tan bumps on the stem that cannot be rubbed off easily, honeydew residue Scrape off with a soft toothbrush, apply isopropyl alcohol swab, then neem oil or horticultural oil spray as follow-up