What's eating my euphorbia globosa?

Euphorbia globosa, the globe euphorbia, forms chains of spherical green segments that trap mealybugs in the joints between each globe. This clustering habit makes it especially vulnerable to mealybug infestations. Spider mites occur in dry rooms. Inspect the connective joints between globes at every watering.

White powdery deposits in the constricted joints between globose segments; segments may shrivel or discolour. Use a fine brush soaked in 70% alcohol to treat each joint; apply neem oil spray to the entire plant and repeat weekly for a month.

Fine webbing over the smooth globe surfaces and pale stippling; plant looks dusty in low-humidity interiors. Raise humidity and apply insecticidal soap spray; repeat three times at seven-day intervals.

Flat brownish bumps on the globe surfaces that don't wipe off easily; plant weakens over time. Scrape off scale with a soft brush, then treat with horticultural oil; monitor for regrowth monthly.