Citrus pests, diseases and disorders

Pests, diseases and disorders can affect the external and internal quality of the fruit as well as the overall yield of the crop.

Correct identification of the source of damage is very important for choosing the best management practice. It is also important to use preventative practices to identify potential sources of damage early, as once the damage is noticed it is often too late to stop the problem.

The following provides information on the identity, monitoring and effective management practices of pests, diseases and disorders of citrus in Western Australia.

Pests of citrus

• Aphids in citrus
• Citrus leafminer
• Thrips in citrus
• Scale in citrus
• Citrus gall wasp
• Mediterranean fruit fly
• Citrus whitefly
• Snails
• Green coffee scale (Coccus viridis)
• Fullers Rose Weevil
• Mites in citrus
• Mealybugs in citrus
• Six-spotted mite
• Argentine ants
• Big-headed ants, coastal brown ants

A study into the development of an Integrated Pest Management Strategy for Citrus in Western Australia was completed by Department of Agriculture and Food entomologist Sonya Broughton in 2006.

Diseases of citrus

Diseases are normally the result of a fungal, bacterial or viral infection of the plant or fruit. The organism responsible normally needs to be identified via laboratory diagnostic due to the microscopic nature of the organisms.

• Citrus diseases

Disorders of citrus

Citrus disorders may be caused by nutritional deficits, over watering or other cultural practices.

• Improving citrus quality using gibberellic acid

Other useful publications

• Citrus plant protection guide 2020 available on the New South Wales Department of Primary Industries website.
• Citrus pests and their natural enemies, Integrated Pest Management in Australia, QLD Department of Primary Industries, ISBN 0 7242 6695 X
• Citrus Diseases and Disorders (2004) by Patricia Barkley formerly from New South Wales Industry & Investment (NSW I&I). Another excellent resource for any citrus grower. The comprehensive guide is full of colour photographs and contains information on diseases of fruit, leaves, twigs, roots and trunks, viruses and virus-like diseases, physiological disorders and exotic diseases. The book can be purchased from the NSW Industry & Investment website.
• The Citrus Australia website also contains a comprehensive list of information on the pests, diseases, disorders and exotic threats that affect the national citrus industry.
• Common pests of summer fruit in Western Australia

Exotic threats to WA citrus

Sometimes a new pest or disease may be found in your orchard. This may be an exotic pest that is not present in Western Australia due to state border protection or national quarantine. Some of these include:

• Citrus canker
• Citrus greening (Huanglongbing) and associated vector the Asiatic citrus psyllid
• Queensland fruit fly
• Spiraling whitefly

If you see anything unusual in your orchard contact the Pest and Disease Information Service or call the Exotic Plant Pest Hotline on 1800 084 881.