Context:

• After decimating orange groves in Florida and trees in California and Brazil, citrus greening disease now threatens the key producing region of the Mediterranean, according to researchers.

Other details:

• The disease “has spread since the mid-2000s with a phenomenal speed and impact.
• The only citrus producing region as yet unafflicted, “the Mediterranean can’t remain untouched by citrus greening disease.
• one species of the insect which spreads the disease has already been found on the Arabian peninsula.
• The disease emerged in the first half of the last century in Asia, where it is called yellow dragon disease by the Chinese.
• It is spread by small insects called plant lice or psyllids which jump from tree to tree to suck the sap.
• When they do, they introduce the bacteria which ends up blocking the channels along which the sap flows.
• As the bacteria chokes off the flow of nutrients, the leaves turn yellow, the fruit is deformed, and eventually the tree dies.
• The African psyllid, which spreads a less virulent form of the disease, has already been detected in northern Spain and in Portugal, where trees were rapidly uprooted to prevent any further spread.

Source:TH