What's eating my lace cactus?

Lace Cactus (Echinocereus reichenbachii) is a slender ribbed houseplant admired for its dense lacy spination. Those spines shelter mealybugs effectively, making them the chief pest threat. Scale insects and root mealybugs are secondary concerns. Inspect with a magnifying glass every few weeks — the spine density hides early infestations well.

White cottony fluff hidden deep in the dense lacy spine matrix; feeding causes pale, shriveled stem sections. Apply 70% isopropyl alcohol with a fine-tipped swab directly into spine clusters. Spray neem oil across the whole plant; repeat weekly.

Small brown or gray shell-like bumps on ribs beneath the spines; subtle yellowing around affected areas. Remove with a soft toothbrush and alcohol. Apply neem oil or horticultural oil spray and inspect again in 2 weeks.

Decline and lack of new growth despite good care; white waxy material on roots discovered at repotting. Unpot, clean roots, dry for a day, repot in fresh fast-draining cactus mix. Drench once with dilute systemic insecticide.