What's eating my pencil cactus rhipsalis?

Rhipsalis cereuscula is a spineless, moisture-loving epiphytic cactus whose fleshy pencil-like segments attract mealybugs and scale. Fungus gnats thrive if the potting mix stays too damp. Spider mites can attack in heated, dry indoor rooms. Its pendant habit means pests on lower segments are easily missed — inspect the whole curtain of growth monthly.

White cottony deposits at segment joints and branch axils; sticky honeydew dripping from affected stems Dab joints with isopropyl alcohol on a cotton swab; spray thoroughly with neem oil or insecticidal soap

Small brown bumps fixed at segment nodes; black sooty mould develops below on leaves and surfaces Scrub off with a soft toothbrush, wipe with alcohol, treat with horticultural oil spray

Tiny flies around the pot; larvae damage fine roots in overly moist epiphytic mix, causing wilting Allow the top layer of mix to dry between waterings; use yellow sticky traps; apply Bti drench to the mix