Aphids on pumpkin
The cotton aphid and the peach-potato aphid form colonies on the underside of pumpkin leaves. They suck sap, foul the plants with honeydew and transmit cucurbit mosaic viruses.
Symptom photos
Symptoms
- Colonies of small aphids on the underside of the leaves
- Young leaves curling and puckering
- Sticky honeydew on leaves and fruit
- Black sooty mold growing on the honeydew
- Shoot tips ceasing to grow
What it does to the crop
- Transmission of mosaic viruses that cannot be cured
- Weakened plants and smaller fruit
- Fruit fouled with honeydew and sooty mold
- Young growth deformed
What encourages it
- Warm, still weather from June onwards
- Too much nitrogen and lush growth
- No beneficial insects around the crop
- Weeds acting as a breeding ground for aphids
Prevention
- Check leaf undersides once a week
- Sow nectar plants for ladybirds and hoverflies
- Wash the colonies off with a strong jet of water
- Keep nitrogen feeding moderate
- Clear weeds from around the crop
⚠️ 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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