Pest identification
What's eating my thorny zamia?
Scale insects
Signs: Armored scale crusting on leaflets and stems; yellowing fronds and reduced vigor
Control: Horticultural oil spray applied thoroughly; manual scraping; repeat monthly until clear
Mealybugs
Signs: White cottony masses in the crown and at petiole bases; honeydew and sooty mold
Control: Neem oil or insecticidal soap spray; isopropyl alcohol swabs; isolate from other plants
Eumaeus moth caterpillars
Signs: Bright orange–red gregarious caterpillars that completely strip new fronds to bare midribs
Control: Hand-pick caterpillar clusters; Bt spray on new growth at flush; check undersides of leaflets regularly
Keep thorny zamia pest-free
Healthy plants resist pests best. Get the basics right:
Thorny Zamia pests — FAQ
What is eating my thorny zamia?
Thorny Zamia (Zamia muricata) from Colombia and Venezuela is grown by cycad collectors in tropical or greenhouse settings. Scale insects are the most persistent pest. Mealybugs colonize the crown and leaf axils. In outdoor tropical garden plantings, caterpillars of the Eumaeus moth (a cycad specialist) can rapidly defoliate new growth.
How do I get rid of scale insects on thorny zamia?
Armored scale crusting on leaflets and stems; yellowing fronds and reduced vigor Horticultural oil spray applied thoroughly; manual scraping; repeat monthly until clear
How do I get rid of mealybugs on thorny zamia?
White cottony masses in the crown and at petiole bases; honeydew and sooty mold Neem oil or insecticidal soap spray; isopropyl alcohol swabs; isolate from other plants
How do I get rid of eumaeus moth caterpillars on thorny zamia?
Bright orange–red gregarious caterpillars that completely strip new fronds to bare midribs Hand-pick caterpillar clusters; Bt spray on new growth at flush; check undersides of leaflets regularly