Citrus trees in backyards and orchards in the USA are being killed by a small bug called the Asian Citrus Psyllid (ACP). We want to keep it out of Australia – but we need your help!
The ACP is a small (3-4mm) sap-sucking bug that resembles a small cicada. It can cause direct damage to citrus plants, but its transmission of the bacterial disease huanglongbing (HLB) is its most damaging feature.
HLB, or “citrus greening”, is a destructive disease of citrus and other Rutaceae species that leads to tree decline and death.
Adult Asian Citrus Psyllid (Diaphorina citri) Image credit: David Hall, USDA Agricultural Service, Bugwood.org.
All commercial citrus are affected as well as Australian native citrus and some ornamentals in the Rutaceae family including orange jasmine (Murraya). The disease affects all plant parts and growth stages of citrus, including causing small, hard and misshapen fruit, and tree can die within 5 to 8 years after infection.
There is currently no cure for HLB despite enormous research projects worldwide.
HLB and ACP are widespread in our northern neighbours, including Indonesia, Papua New Guinea, and Timor Leste, which poses a significant threat to Australia.
Asian Citrus Psyllid (Diaphorina citri) nymph Image credit: Jeffrey w. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org.
It’s why Australian citrus growers across the country and other industry experts watch for any sign of the pest.
Grower Adrian Chapman, based in Mildura, Victoria, said improving pest and disease detection is a priority for his business and the citrus industry as a whole.
“All us growers need to use our time in the field and the orchard as surveyors for the industry,” Adrian said.
“We need to be vigilant and look for potential exotic pests or disease in our own orchards, because that’s where a potential outbreak will occur – in our own backyards.
“When we find something questionable, we need to know where to send that information to have it identified to make sure it’s not a threat to our industry.”
Orange citrus trees heavily infected with huanglongbing (HLB) or citrus greening.
Adrian visited the USA this year and witnessed the devastation ACP and HLB have caused in the USA.
“I’ve seen firsthand the devastation exotic diseases can cause,” Adrian said.
“Not only to the trees but the farming community and its wider spectrum. Growers and the general public need to be aware of what these diseases can cause.”
Every gardener can play their part by becoming familiar with exotic pests like the ACP. If they see something unusual, they should call the Exotic Pest Plant Health line on 1800 084 881.
So to protect our great citrus culture, keep your eyes open when working in the garden.
