Psyllids - Psyllid Yellows

Recently a new insect pest an associated plant disease has been introduced to New Zealand. Psyllids are small (3mm) flies that attack potatoes, tomatoes, capsicums, tamarillos and cape gooseberries amoung others. The insect itself does not cause the disease but it transmits a bacterial infection (Liberibacter) that infects the plants and causes yellowing and loss of production. Sometimes the infection can kill the plants.

The psyllid injects the liberibacter into the plant tissues when feeding on the crops and new psyllids are infected in turn when they feed.

The adult psyllid is a small (3mm) insect with clear wings. Psyllid eggs are tiny pale ovoids attached to the hairs on the leaves of plants. The nymphs are about 2mm in length and are usually found on the underside of the plant leaves. They look a little like scale insects.

Control of Psyllid Yellows

There are no treatments for the bacterium available at this time. The control of the disease requires control of the psyllids.

1. Avoid bringing infected plants into your garden.
2. Remove and dispose of any plants that show symptoms of infection.
3. During winter remove all plants that could be host to infection.
4. Inspect susceptible plants regularly for signs of infection or infestation with psyllids.
5. Remove and bag as many infected/infested material as possible.
6. Apply Kiwicare NO Insects Maldison insecticide to plants, paying particular attention to the underside of leaves where adults and nymphs live.
7. Maldison will not kill eggs so repeat treatments will be necessary to kill adults and nymphs and break the life cycles.
8. Follow product instructions for use on crops carefully.