Asian citrus psyllid

Have you seen this pest?

Asian citrus psyllid poses a serious threat to backyard citrus and the Citrus industry.

Keeping Asian citrus psyllid out of the country is a national priority.

What should I do?

• Report immediately.
• Share your photo/s with us using this online form if you think you have found this pest.
• Call the Exotic Plant Pest Hotline 1800 084 881.

Why is it a pest of concern?

Feeding by Asian citrus psyllid nymphs and adults can cause serious damage to budbreak flushes and growing points, leading to dwarfing of tree and fruit. Heavy populations cause blossom and fruitlet drop. Black sooty mould can occur as a result of excess honeydew excreted by the psyllid.

It can transmit the High priority bacterium that causes huanglongbing (HLB) disease or citrus greening and from tree to tree via feeding. Symptoms of HLB include yellowing of leaves with a blotchy mottled pattern. Trees lose their leaves and have extensive twig and limb dieback.  Fruit produced is small, lopsided, unevenly coloured and bitter tasting.  Eventually, the tree stops bearing fruit and dies.

What is it?

The Asian citrus psyllid (Diaphorina citri) is a harmful pest that feeds on both native and cultivated citrus plants. Its feeding can stunt the growth of young plants by inhibiting shoot growth and causing leaf deformation. Additionally, it can transmit a disease called huanglongbing, also known as citrus greening, which can kill a tree within five years with no known cure.

All commonly grown citrus varieties are vulnerable to this disease.

Pest profile

Appearance

• Adults: Measure between 2–4 mm long with mottled brown bodies and light brown heads. Their wing are translucent with white and light brown spots. Males are smaller than females.
• Nymphs: Flattened, orange-yellow in color, ranging from 0.3 mm to 1.7 mm. They undergo five moulting stages before becoming adults.
• Eggs: Pale when newly laid, turning yellow then bright-orange before hatching. They are elongated and almond-shaped, around 0.3 mm long.

Identifying signs

• Where to look: Predominantly found on young leaves and shoots of citrus plants, with eggs laid in batches on growing shoots or unfurled leaves.
• Distinct markings: Look for a waxy tubule with a bulbous end on young leaves, a sign of the psyllid's presence.

Host Plants in Australia

• Primarily infests plants from the Rutaceae family, especially grapefruit, lemons, and limes. Indigenous Australian citrus species are also at risk.

Life cycle

• Prefers temperatures between 13 and 30°C and completes its life cycle in 14 – 50 days, with multiple overlapping generations per year.

Distribution and dispersal

• Originated in eastern Asia or the Indian subcontinent and has spread widely across various continents.
• Weak flyers but can be dispersed over long distances by strong winds.

Prevention

• Be vigilant when transporting plants to prevent the introduction of psyllids.
• Monitor imported host plants carefully to prevent the spread of the pest.