Mealybugs on String of Pearls — Hidden in the Bead Tangles
String of Pearls (Curio rowleyanus (formerly Senecio rowleyanus))
Symptoms
- white cottony masses visible between beads or where strands tangle together
- white waxy powder on beads or along stems
- sticky honeydew on beads and on surfaces below the hanging plant
- beads yellowing or losing firmness near colonies
Causes
Colonies establishing in sheltered strand tangles
Where multiple strands of String of Pearls cross or tangle, the protected interior creates an ideal mealybug habitat: warm, sheltered from light, and difficult to reach. Mealybugs (Planococcus citri and related species) establish colonies in these locations and can remain undetected for weeks in a dense hanging plant.
Introduction from nearby infested houseplants
Crawlers (juvenile mealybugs) walk between plants in a collection. In a humid, warm growing environment where multiple plants are grouped for humidity, mealybugs spread readily. String of Pearls' trailing form, which often touches nearby plants or surfaces, provides easy transmission routes.
How to Fix It
- 1
Isolate the plant from other houseplants.
- 2
With one hand gently parting the tangled strands and a cotton swab dipped in 70% isopropyl alcohol in the other, touch each visible colony directly; the tight bead spacing makes this slow going, but it's the only way to reach mealybugs wedged between adjacent beads.
- 3
Mix a neem-oil spray at the standard 2-teaspoons-per-quart dilution, adding a touch of dish soap to help it cling to the beads' smooth, waxy surface rather than beading off, and mist thoroughly into the strand tangles; repeat every 7 days for 4 weeks to cover successive crawler hatches.
- 4
Check the root zone for root mealybugs at the next repotting opportunity. White powder on roots indicates a separate soil-dwelling infestation that requires root washing and repotting.
Prevention
- Inspect strand tangles monthly — use a flashlight to see into the dense bead clusters
- Keep any newly purchased plant isolated for about 3 weeks before it hangs near your String of Pearls
- Avoid letting String of Pearls strands touch other plants
Quick Summary
| Plant | String of Pearls (Curio rowleyanus (formerly Senecio rowleyanus)) |
|---|---|
| Category | Pests |
| Likely causes | Colonies establishing in sheltered strand tangles, Introduction from nearby infested houseplants |
| Fix steps | 4 steps — see above |