Pests of plants: Asian citrus psyllid

Diaphorina citri

Profile The Asian citrus psyllid is a small, sap-sucking insect. It can carry and transmit a deadly disease of citrus (Huanglongbing or citrus greening) for which there is no cure. Even the psyllid on its own is a serious pest of young citrus trees and has established in Florida.

Identification The adults are 3-4mm long with brown markings on the wings. They feed mostly on the veins of the young leaves and adopt a ‘head-down, tail-up’ position when feeding. The young stages are pale brown and lie flat on the blade of the leaf while feeding. This pest’s favourite food plant is the ‘mock orange’ commonly planted as an ornamental shrub.

Distribution Widespread in Asia, present in New Guinea, where Huanglongbing is also present and killing citrus trees.

Threat The psyllid is a weak flier and is most likely to be spread over larger distances by transport as eggs or nymphs on citrus or ‘mock orange’ plants. Introduction of this pest and the disease it spreads would destroy home-grown citrus trees and devastate the citrus industry.

Keep a Top Watch Don’t move parts of citrus plants from New Guinea into Torres Strait. Don’t move citrus or plant cuttings from the northern islands of Torres Strait. Look out for new insects on citrus trees. Watch for any loss of health in your citrus trees. Contact your local Quarantine officer if you see any unusual, small insects or loss of health in your citrus trees.