What's eating my huernia thuretii?

Huernia thuretii is an indoor stapeliad succulent susceptible to the same pests that trouble most stapeliads: mealybugs are the main concern, followed by root mealybugs and fungus gnats in poorly drained conditions. Keeping the plant in bright light with excellent drainage and inspecting it monthly will prevent most infestations.

Cottony tufts at stem joints and growing tips; plant growth slows; honeydew makes stems look shiny or sticky. Dab colonies with alcohol, then apply insecticidal soap or neem oil spray every 7–10 days for three to four cycles. Remove heavily infested segments.

Wilting despite adequate moisture; white powdery deposits coating roots visible on unpotting. Unpot, remove all soil, rinse roots thoroughly, and drench with a neem or imidacloprid solution. Allow roots to air-dry briefly, then repot in sterile gritty mix.

Swarms of tiny dark gnats near soil surface; larval feeding damages fine roots, particularly on younger plants. Reduce watering frequency drastically and top-dress with coarse grit. Treat soil with Bti granules or hydrogen peroxide solution (1 part 3% H₂O₂ to 4 parts water).