What's eating my echinopsis?

Echinopsis cacti are most troubled by mealybugs and root mealybugs indoors, which hide in spine clusters and at the roots. Scale insects and spider mites occasionally attack, especially in warm, dry conditions. Inspect regularly at the base and between spines; treat early to prevent a colony establishing in the dense areoles.

White waxy cottony clusters in spine axils and at the soil line; stunted or distorted growth Dab with a cotton swab dipped in 70% isopropyl alcohol; follow up with neem oil spray; isolate the plant

Pale, slow-growing plant that does not respond to watering; white powdery colonies visible on roots when unpotted Unpot, wash all soil off roots, soak roots in diluted neem solution, repot in fresh dry cactus mix

Brown or tan hard bumps on the stem that do not brush off; sticky honeydew may coat the surface Scrape off with a soft toothbrush, wipe with alcohol-soaked cloth, treat with horticultural oil