New Moth Species Invades Italy's Vineyards

 

 

A moth with a taste for Chardonnay leaves, which has infested vineyards across northern Italy, is a new species of leafminer, scientists say.  The pest was first discovered by Italian scientists in 2006, but they were unable to identify it.

Now, by examining a snippet of the moth's genetic code, researchers have confirmed that it is a previously unnamed species.  The Italian team enlisted the help of insect expert Erik van Nieukerken from the Netherlands Centre for Biodiversity in Leiden.

"We first turned to the [scientific] literature to find out what was already known, which was appallingly little for this group [of moths]," Dr van Nieukerken told BBC Nature.   He and his colleagues used a method known as DNA barcoding to examine a section of the insect's genetic code.

• Leafminers lay their eggs on the underside of leaves
• When the larvae, or caterpillars, hatch, they tunnel through the leaves, eating the most easily digestible layers as they go
• There is evidence to suggest that some plants have evolved leaf markings that mimic leafminer tracks, in order to "fool" the pests into thinking that the plant has already been attacked

"I figured out that this one, despite being quite common in North America, had no name," he recalled.

The new species, which now bears the name Antispila oinophylla, had previously been confused with a North American species (Antispila ampelopsifoliella), which feeds on Virginia creeper.

Only the genetic studies revealed it to be a different species with a taste for grapevines. Its native range is across eastern North America, where it feeds on several species of wild grapes. So far, the species has been found in vineyards in Italy's Trento and Veneto regions, spreading and increasing in population since it was first recorded.

Having observed the moths in the field, the scientists say that the insect seems to have a preference for the leaves of Chardonnay, Cabernet Sauvignon and Muscat grapes, but they added that the economic impact of this particular pest was not yet clear.  The researchers do not know exactly how the moth arrived in Italy, but Dr van Nieukerken said that it was very easy for the cocoons containing the larvae to be accidentally transported with plant material.  "They're very small and exactly the same colour as the leaves," he said "So if you were carrying plants, you would probably not notice them."

The scientist said that another species from this same group had been discovered in commercial walnut crops and that more needed to be known about the insects. "This group is very poorly studied,".
"If you know exactly what it is and where it belongs, if you know its evolutionary history.... you can understand better how to control it."