Pests & diseases › Red Spider Mite
Red Spider Mite
Microscopic mites on undersides of greenhouse crop leaves. Fine webbing in bad attacks. Worst in hot dry conditions.
Symptoms
- Fine pale speckling on leaves
- Leaves turning bronze, then dropping
- Fine cobweb-like webbing across shoot tips and between leaves
- Use a magnifier — red-brown specks moving on leaf undersides
Lifecycle
Reproduce explosively in hot dry conditions — a single mite to thousands in three weeks.
What to do
- Damp down greenhouse floors daily to raise humidity (mites hate humidity)
- Mist plants morning and evening
- Phytoseiulus persimilis biological control — predatory mite, very effective indoors
- Strip out and bin badly-affected plants
If it's bad
- SB Plant Invigorator — physical-action spray, not a true pesticide
Stop it coming back
- Keep greenhouse humidity high
- Inspect every plant brought in
- Clear out and disinfect greenhouse over winter
Crops it goes for
Aubergine
Chilli Pepper (Hot)
Chilli Pepper (Medium)
Chilli Pepper (Mild)
Chilli Pepper (Super Hot)
Cucumber
Cucumber (Greenhouse)
Fig
Grape (Greenhouse)
Melon
Sweet Pepper
Watermelon
Plan the plot, track every sowing, cook the harvest
Sowing reminders and harvest forecasts for your own frost dates, the Seed Tin, Scan Centre for any label or packet, and the Potty Mouth Garden Club. Free to start.