Exercise Yellow Dragon tests readiness for exotic disease of citrus

March 12, 2015

Australia’s readiness for an incursion of the exotic disease of citrus, huanglongbing (HLB) or yellow dragon disease, was boosted this week when Plant Health Australia (PHA) ran Exercise Yellow Dragon over two days.

The exercise simulated an incursion discovered in Sydney of HLB and its insect vector, Asiatic citrus psyllid (ACP), a combination that has caused devastation of citrus crops elsewhere in the world. It was held at the NSW Department of Primary Industries’ Elizabeth Macarthur Agricultural Institute near Camden in NSW.

PHA’s Dr Stephen Dibley said that the aim of the exercise was to assess the effectiveness of Australia’s planned eradication strategies for HLB and ACP, in a scenario where the disease was first detected in an urban setting.

Participants were those representatives from government and industry who would be involved in a real exotic pest incursion. Together they stepped through elements that a real eradication response would involve.

“During the exercise we considered how aspects of a response would work in an urban environment,” Dr Dibley said.

“This included pest eradication options, tracing of host material and other items that could carry the pests, together with how to engage the community in the response.”

“People at the exercise recognised the importance of informing the public who would be able to assist in a response in ways such as checking citrus plants in their backyards, reporting anything unusual and abiding by quarantine zone restrictions,” Dr Dibley added.

Judith Damiani, Chief Executive Officer of Citrus Australia, said that Exercise Yellow Dragon had been very useful for everyone involved.

“You can sit at a desk and make plans for a theoretical incursion of a serious pest incursion like HLB, but a dress rehearsal like this makes everyone really consider all the details of how it would work,” Ms Damiani said.

“We feel that Australia is now better prepared to deal with the real thing, though of course we hope we never have to face HLB in Australia,” Ms Damiani added.

Participants also heard first-hand accounts from a recent study tour to affected states of the USA and were shown the diagnostic facilities at the institute which would be used in testing for HLB in a real incursion.

Exercise Yellow Dragon is part of the Citrus Biosecurity Project, which is funded by Horticulture Innovation Australia Limited and jointly managed by PHA and Citrus Australia.

HLB, also known as citrus greening disease is not a human health issue, but it kills citrus trees. There is no known cure.  It is considered one of the most serious plant diseases in the world and affects orchards throughout Asia, the Middle East, South and Central America, the Caribbean and some southern states of the USA. It’s also present in regions close to Australia including Indonesia, East Timor and Papua New Guinea.

If HLB was to establish in Australia it would threaten citrus orchards as well as backyard citrus fruit trees, native citrus and ornamental citrus such as murraya.