What's eating my curiosity plant?

Curiosity Plant (Cereus forbesii 'Spiralis') is a striking spiraled columnar cactus kept indoors. Mealybugs are its chief threat, hiding in the twisted rib grooves. Scale insects and spider mites also occur in dry indoor environments. The spiral form creates extra hiding places along the ribs — run a swab along each groove to spot early infestations before they spread.

White cottony deposits lodged in the spiral grooves; affected sections look dull and pale; growth stalls. Work isopropyl alcohol on a cotton swab along every rib groove; apply neem oil spray to the whole plant weekly for 4 weeks.

Brown or tan waxy bumps attached to the stem ribs; honeydew residue and possible sooty mold develop. Scrape off gently with a soft toothbrush dipped in rubbing alcohol; follow with insecticidal soap spray every 10 days.

Fine webbing visible in the rib recesses and faint dusty stippling on the green stem in low-humidity rooms. Improve air circulation and humidity near the plant; apply neem oil spray and repeat weekly until clear.