Spider mites on tomato
The two-spotted spider mite sucks sap from the underside of tomato leaves. The first sign is fine, pale stippling on the blade; in dry air the population grows so fast that leaves turn rusty and shrivel.
Symptom photos
Symptoms
- Fine, pale stippling and mottling on the upper leaf surface
- Delicate webbing on the leaf underside and along the veins
- Rusty-brown, drying leaves in a heavy attack
- Very small, moving mites visible with a hand lens
- Leaf shrivelling working up from the bottom of the plant
What it does to the crop
- Leaf loss and sunscald on the fruit
- Stunted growth and a drop in yield
- Plants dying off early in the tunnel
- Very fast spread to neighbouring plants
What encourages it
- Temperature above 25°C with humidity below 50%
- Growing under cover without misting or ventilation
- Drought and water stress
- Too much nitrogen
Prevention
- Raise humidity by damping down the paths
- Check leaf undersides weekly from June
- Introduce the predatory mite Phytoseiulus persimilis
- Remove the worst-affected leaves
- Disinfect the tunnel and clear debris after the season
⚠️ Before you reach for a spray
This atlas is informational and still growing — different diseases can look almost identical. Confirm the diagnosis and read the product label before applying any plant protection product. If you are unsure, ask your local extension or advisory service.
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