Pest identification
What's eating my old man of the andes?
Mealybugs
Signs: White insects easily mistaken for the cactus's own wool; yellowing or soft patches on the stem beneath
Control: Part the hair and dab each colony with 70% isopropyl alcohol; apply systemic neem soil drench monthly
Scale insects
Signs: Hard lumps felt along the ribs under the wool; sooty mould developing from honeydew
Control: Brush off physically; scrub with alcohol; apply horticultural oil spray to the entire stem surface
Spider mites
Signs: Webbing woven through the white hair; bronzed or silvery patches on the stem when wool is parted
Control: Spray with dilute neem oil; move to a well-ventilated spot; avoid placing near dry heat sources
Keep old man of the andes pest-free
Healthy plants resist pests best. Get the basics right:
Old Man of the Andes pests — FAQ
What is eating my old man of the andes?
Old Man of the Andes (Oreocereus celsianus) is most threatened by mealybugs, which burrow into its thick woolly hair and are nearly invisible. Scale insects and spider mites also attack the hidden stem surface. Parting the wool regularly and checking the base are essential to catching infestations before they take hold.
How do I get rid of mealybugs on old man of the andes?
White insects easily mistaken for the cactus's own wool; yellowing or soft patches on the stem beneath Part the hair and dab each colony with 70% isopropyl alcohol; apply systemic neem soil drench monthly
How do I get rid of scale insects on old man of the andes?
Hard lumps felt along the ribs under the wool; sooty mould developing from honeydew Brush off physically; scrub with alcohol; apply horticultural oil spray to the entire stem surface
How do I get rid of spider mites on old man of the andes?
Webbing woven through the white hair; bronzed or silvery patches on the stem when wool is parted Spray with dilute neem oil; move to a well-ventilated spot; avoid placing near dry heat sources