What's eating my levy's huernia?

Levy's Huernia is a rare clustering stapeliad kept as a houseplant, most at risk from mealybugs between its ribbed stems and root mealybugs in the growing medium. Spider mites can appear in hot dry air. Flies drawn to the flowers are pollinators. Keeping the plant in a well-ventilated spot reduces most pest pressure.

Cottony white deposits lodged between stems and along the stem ribs; affected areas shrivel or discolor Spot-treat with 70% isopropyl alcohol; apply a diluted neem oil spray over all stems; repeat weekly for 4 weeks

Stems deflate and plant stops clustering; white waxy material coats roots discovered only at repotting Unpot completely, clean roots, soak briefly in insecticidal soap solution, dry thoroughly, repot in sterile gritty mix

Fine pale speckling on stems; delicate webbing in corners between stems in hot, low-humidity indoor conditions Improve air movement around plant, wipe stems with damp cloth, apply neem oil or insecticidal soap spray weekly