Alarm is spreading in Tuscany following the arrival in the region of a Chinese bug which attacks chestnut trees and devours their fruit.
The 'oriental chestnut gall wasp', which is 2.5 cm long and has a black body and yellow legs, is common in Asia and the United States but has only ever made two short-lived forays into Italy.
Recent sightings of the insect in Tuscany are grim news for local chestnut growers who take enormous pride in their product and have won European Union recognition for its distinctive characteristics.
The Chinese bugs are capable of spoiling up to 80% of a large chestnut tree's production in a single season. They are also extremely difficult to get rid of.
"This is a high-risk situation," said Simone Tofani, of the La Legnaia farm cooperative near Florence. "This insect's attacks can cause very serious damage indeed".
When the chestnut wasp takes up residence in a tree, swellings appear on leaves and branches. Inside these 'galls' the insect eggs gradually become larva and in the spring they emerge as insects. They immediately begin eating the new shoots and the tree's young fruit.
"There aren't many options when it comes to fighting the chestnut wasp," said experts at the Tuscan environmental protection agency ARPAT.
"Using chemical agents is out of the question in woodland and using a bacteriological approach takes too long. What's left is prevention. You avoid transporting plants and cuttings from infested areas".
The insect, whose scientific name is Dryocosmus kuriphilus, was last seen was last seen in Viterbo, near Rome, in 2005. Three years earlier it had cropped up in Piedmont.
Both outbreaks appeared to have been contained thanks to an agriculture ministry decree that enforced draconian preventive measures.
But the bug seems able to strike and flourish at will. It disappears for a time and reappears later somewhere else.
The wasp is able to travel relatively short distances by itself. A big danger however is that the insect larva are transported by chestnut farmers who inadvertently take cuttings from infected trees.
ARPAT has appealed to anyone who sees the little black beasts with the yellow legs or curious swellings on a chestnut tree to report the sighting immediately to authorities.
The infected parts of trees must be found and destroyed by June, otherwise the insects will emerge and the females will fly off to lay eggs in new, uninfected chestnut trees.
