A blight called citrus greening is killing orange, lemon and other such trees worldwide and could soon do the same in Europe. As Horizon magazine reports, tiny infected insects known as psyllids are responsible for spreading the scourge, which turns tree leaves yellow and the citrus fruits bitter.
The pest originated in China, where it’s also known as Huanglongbing (HLB), or yellow dragon disease. While the psyllids in Asia are causing the most damage, an African variety of the insect that is another vector of HLB has been found in Spain and Portugal.
‘The disease is highly destructive to the citrus,’ said Leandro Peña, a biologist at the Polytechnic University of Valencia in Spain. ‘A range of varieties of citrus that are available nowadays to the consumer may disappear if this disease reaches our continent.’
This is where an EU-funded project called PRE-HLB could offer reassurances. The research, which started in 2019, aims to develop a comprehensive strategy to protect Europe from citrus greening. Experts from nine countries – including the Americas and Asia – are trying to prevent the disease from coming to Europe by increasing knowledge of how it spreads. The researchers also want to be prepared in case the disease does reach Europe, so they’re developing measures to soften the impact, control it and eventually eliminate the pest if needed.
Furthermore, long-term solutions, including breeding new citrus plants resistant to the pest and coming up with methods to treat the disease such as biopesticides, are also being investigated. The project is due to end in November this year.