What's eating my consolea moniliformis?

Consolea moniliformis, a tall tree-like cactus from the Caribbean often kept indoors or in warm conservatories, is susceptible to cochineal scale and mealybugs on its flat pads. Fungus gnats can trouble rooted cuttings in peat-heavy mixes. Its spiny pads limit many pests, but scale insects are the main watch-out.

Bright white cottony tufts on pad surfaces concealing red-bodied insects; pads yellow and shrivel. Blast off with a strong water jet outdoors; scrub pads with diluted dish soap and apply horticultural oil.

White waxy clusters at pad joints and areoles; sticky honeydew leads to sooty mold growth. Apply rubbing alcohol directly with a cotton swab; follow with neem oil spray on all pad surfaces.

Larvae chew fine roots of young plants; adults are a nuisance but larvae cause more direct damage. Allow soil to dry fully between waterings; use yellow sticky traps and apply Bacillus thuringiensis israelensis (Bti) drench.