Spider Mites 🐛
Tetranychus urticae and relatives (family Tetranychidae)
At a glance
- Looks like: Almost invisible specks; fine webbing between leaves and stems
- Tell-tale sign: Pale stippling/speckling on leaves; a dusty, faded look
- Severity: Serious — populations explode fast in warm, dry air
How to identify
Not insects but tiny arachnids, often less than a pinhead. You’ll usually notice the damage before the mites: tiny pale dots (stippling) on upper leaf surfaces as they suck out cell contents, giving leaves a faded, dusty, or bronzed appearance. In bad cases you’ll see fine silk webbing in leaf axils and across growing tips. Confirm by tapping a leaf over white paper — moving specks are mites. A 10× loupe shows oval bodies, often with two dark spots.
Damage
They drain plant cells, causing speckling, yellowing, leaf drop, and — if unchecked — death. They reproduce explosively in hot, dry conditions (and indoors in winter heating).
Treatment (least-toxic first)
Following Integrated Pest Management:
- Physical: Isolate the plant. Rinse thoroughly, especially leaf undersides — a forceful shower knocks down populations dramatically. Wipe leaves.
- Raise humidity / reduce stress: Mites hate humidity; group plants, mist, and keep the plant well-watered. Dry, stressed plants are mite magnets.
- Insecticidal soap or horticultural oil: Spray thoroughly (undersides too), repeating every 5–7 days for 3–4 cycles to catch newly hatched mites.
- Last resort: A miticide — rotate active ingredients, since mites develop resistance quickly.
Prevention
Quarantine new plants for a couple of weeks; keep humidity up; inspect undersides regularly. Avoid drought stress.
Affects (in this guide)
Monstera · Fiddle-Leaf Fig · Pothos · Peace Lily · Snake Plant (rare)