Spider mites on monstera
Clemson lists spider mites among the pests of philodendron, which it calls a close relative of monstera, and says they trouble plants kept indoors all year most. Look for pale speckling on the upper leaf that fades, then bronzes or yellows. Spray the leaves forcefully with water, undersides too, or use insecticidal soap. N. californicus suits dry rooms better than Phytoseiulus: Arbico lists tropical foliage plants and gives 40–60% humidity as its range.
At a glance
- Damage
- Pale stippling, bronzing, webbing under leaves
- Type
- Sap feeding
- Settings
- Under glass, Field, Garden, Indoors
- Threshold
- Pale speckling on the upper leaf — no numeric threshold
- Release
- Neoseiulus californicus
- Rate
- 1–4 per plant, every two weeks, 2–3 times (Arbico; Cornell gives the same per-plant figure)
How to confirm it
Confirm with a 10× hand lens on the leaf underside: oval yellowish-green mites with a dark blotch on each side, round translucent eggs, white cast skins and fine webbing. Tap a leaf over white paper and they walk off.
Identification, lifecycle, degree days and every control option are on the full Two-spotted spider mite profile. Not sure it is this pest? Answer four questions about the damage.
Work it out
How many do I need?
Carries Neoseiulus californicus and monstera & aroids through so nothing is re-entered. Open the calculator →