Common pests whitefly

Common pests whitefly

These small but destructive pests often appear on plants in large numbers in greenhouses and conservatories.

Time to do: spring-summer

Whitefly suck the sap of plants such as tomatoes and cucumbers, often hiding on the underside of their foliage. They also attack young plants and seedlings, as well as houseplants.

These pests are difficult to eradicate once they become established, so check plants regularly and take action as soon as you spot any. They weaken plants and disfigure them with spots on the leaves, sticky honeydew and sooty moulds.

in the greenhouse, a biological control such as the tiny parasitic wasp Encarsia formosa can be used a good garden centre will have details of suppliers, or search online. Alternatively, hang yellow sticky cards above plants in the greenhouse to trap them. in the house, use a small hand-held vacuum cleaner to suck them off the plants.

Sprays are available for whitefly control.

Follow the directions carefully as these only kill whitefly and not their eggs. Regular spraying is required to kill newly emerged adults before they lay more eggs.

TIP The yellow traps catch whitefly that fly up when disturbed. So brush the foliage of infected plants with your hands to get the pests moving.