What's eating my hedgehog cactus?

Hedgehog Cactus (Echinopsis subdenudata) is a compact, nearly spineless indoor cactus that is particularly prone to mealybugs, which exploit its soft ribs. Scale insects and root mealybugs in the soil are also common threats. Its lack of spines makes pest inspection easy — check the ribs, base, and roots if growth stalls unexpectedly.

White cottony deposits along the rib edges and at the crown; sluggish growth and soft spots. Treat with 70% isopropyl alcohol on a swab; follow up with neem oil spray on the whole plant weekly for a month.

White waxy clusters on the roots visible when repotting; sudden wilting despite adequate moisture. Unpot, wash all soil from roots, let dry, then repot in fresh gritty compost; drench with systemic insecticide if severe.

Small hard brown bumps on the rib surface; sticky honeydew deposits and potential sooty mold. Physically remove with rubbing alcohol and a soft brush; apply insecticidal soap every 10 days until clear.