Pest identification
What's eating my sea urchin cactus?
Mealybugs
Signs: White cottony clusters at the base, between ribs, or near the areoles; slow growth and yellowing.
Control: Dab with a cotton swab soaked in 70% isopropyl alcohol; follow up with neem oil spray weekly for 3–4 weeks.
Scale insects
Signs: Hard brown or tan bumps fixed to the stem surface; sticky honeydew residue and stunted growth.
Control: Scrape off with a soft toothbrush, then apply isopropyl alcohol or insecticidal soap; repeat every 10 days.
Spider mites
Signs: Fine webbing between spines and ribs; tiny rust-colored speckling on the stem surface.
Control: Raise humidity, spray the plant with water to dislodge mites, then treat with neem oil or a miticide spray.
Fungus gnats
Signs: Larvae chew fine roots in overly moist soil, causing sudden wilting or failure to thrive despite good light.
Control: Let soil dry completely between waterings; apply a Bacillus thuringiensis var. israelensis (Bti) drench or use yellow sticky traps.
Keep sea urchin cactus pest-free
Healthy plants resist pests best. Get the basics right:
Sea Urchin Cactus pests — FAQ
What is eating my sea urchin cactus?
Sea Urchin Cactus (Echinopsis oxygona) is most threatened by mealybugs and scale insects when grown indoors, and by fungus gnats when overwatered. Root rot from soggy soil is a common companion problem. Spider mites can appear in hot, dry indoor conditions. Inspect the base and spines regularly for cottony or waxy deposits.
How do I get rid of mealybugs on sea urchin cactus?
White cottony clusters at the base, between ribs, or near the areoles; slow growth and yellowing. Dab with a cotton swab soaked in 70% isopropyl alcohol; follow up with neem oil spray weekly for 3–4 weeks.
How do I get rid of scale insects on sea urchin cactus?
Hard brown or tan bumps fixed to the stem surface; sticky honeydew residue and stunted growth. Scrape off with a soft toothbrush, then apply isopropyl alcohol or insecticidal soap; repeat every 10 days.
How do I get rid of spider mites on sea urchin cactus?
Fine webbing between spines and ribs; tiny rust-colored speckling on the stem surface. Raise humidity, spray the plant with water to dislodge mites, then treat with neem oil or a miticide spray.
How do I get rid of fungus gnats on sea urchin cactus?
Larvae chew fine roots in overly moist soil, causing sudden wilting or failure to thrive despite good light. Let soil dry completely between waterings; apply a Bacillus thuringiensis var. israelensis (Bti) drench or use yellow sticky traps.