What's eating my huernia hystrix?

Huernia hystrix, a spiny stapeliad succulent grown indoors, is most threatened by mealybugs hiding in its stem angles. Spider mites and root mealybugs also attack in dry indoor conditions. Inspect stems and soil regularly, and isolate any new plants for two weeks before adding them to your collection.

White cottony fluff tucked into stem angles and joints; sticky honeydew residue; distorted or stunted new growth. Dab individual bugs with a cotton swab dipped in 70% isopropyl alcohol. For heavier infestations spray with insecticidal soap or neem oil solution, repeating every 7–10 days for three cycles.

Plant wilts despite adequate watering; white powdery coating visible on roots when unpotted. Knock off all soil, rinse roots under running water, then soak in a dilute neem or imidacloprid drench. Repot into fresh, sterile cactus mix.

Fine stippling on stem surfaces; very fine webbing between stems in severe cases; overall dull, dusty appearance. Raise humidity around the plant and wipe stems with a damp cloth. Apply neem oil or a miticide spray weekly for three weeks. Keep away from heat vents.