Pest identification
What's eating my optical plant?
Mealybugs
Signs: Cottony white deposits between leaf lobes or at the plant base; soft or collapsing leaf tissue
Control: Apply 70% isopropyl alcohol with a fine brush; treat base with diluted neem oil; repeat fortnightly
Root mealybugs
Signs: Persistent shrivelling unresponsive to seasonal watering; white waxy colonies found on roots at inspection
Control: Unpot, rinse roots thoroughly, soak in systemic insecticide or neem, repot in fresh mineral grit mix
Fungus gnats
Signs: Adults hover near pot; larvae injure fine roots, particularly in seedlings grown in peat-based mixes
Control: Ensure a purely mineral, very free-draining substrate; top-dress with gravel; apply Bti drench if needed
Keep optical plant pest-free
Healthy plants resist pests best. Get the basics right:
Optical Plant pests — FAQ
What is eating my optical plant?
Optical Plant (Lithops optica), including the striking 'Rubra' form, is susceptible to the same pests as all Lithops. Mealybugs are the most common, hiding between the near-split leaf pair. Root mealybugs can persist undetected. Because Lithops optica undergoes a long dry dormancy, resist watering urges — overwatering causes far more deaths than pests ever do.
How do I get rid of mealybugs on optical plant?
Cottony white deposits between leaf lobes or at the plant base; soft or collapsing leaf tissue Apply 70% isopropyl alcohol with a fine brush; treat base with diluted neem oil; repeat fortnightly
How do I get rid of root mealybugs on optical plant?
Persistent shrivelling unresponsive to seasonal watering; white waxy colonies found on roots at inspection Unpot, rinse roots thoroughly, soak in systemic insecticide or neem, repot in fresh mineral grit mix
How do I get rid of fungus gnats on optical plant?
Adults hover near pot; larvae injure fine roots, particularly in seedlings grown in peat-based mixes Ensure a purely mineral, very free-draining substrate; top-dress with gravel; apply Bti drench if needed