What's eating my living stones?

Living Stones (Lithops karasmontana) are tiny, slow-growing mimicry plants that seldom attract pests. Mealybugs — particularly root mealybugs — are the main threat, feeding on the fleshy taproot undetected. Fungus gnats breed in any damp soil. Spider mites are rare but possible. Incorrect watering causes far more losses than any insect pest.

White waxy powder on roots visible only when unpotting; plants shrivel or fail to plump up despite correct water schedule. Unpot, remove all soil, rinse roots, and soak briefly in diluted insecticidal soap solution; repot in fresh mineral-heavy succulent mix and withhold water for a week.

White fluff at the fissure between the two leaves or at the soil line; honeydew residue attracts sooty mold. Dab carefully with an alcohol-tipped cotton swab, avoiding the leaf fissure; apply neem oil sparingly at the base — do not soak the leaves.

Larvae in damp soil damage fine surface roots; adult gnats hovering around the pot are a sign of overwatered compost. Use a mineral top-dressing (coarse grit or perlite); allow soil to dry completely between waterings; use yellow sticky traps for adults.