Rome turns to ladybirds to save the city's pine trees

Rome seeks ways of stopping a deadly parasite from killing the city's pine trees, including natural methods.

Rome's umbrella pine trees are at serious risk due to a killer parasite - the pine tortoise scale - with efforts gaining pace to save the city's skyline before it is too late.

The Lazio region around Rome recently announced that it has allocated half a million euro to fund the battle to save the capital's trees from the cochineal insect which arrived in Italy from North America in 2015.

There are also numerous private and public operations underway using both organic and chemical treatments against the sap-eating parasite (toumeyella parvicornis) whose activity can kill trees within two years.

The Coccinella Libera Tutti project aims to fight the pine tortoise scale using ladybirds - coccinelle in Italian - by releasing the colourful insects in various green areas of the capital.

This biological fight against the parasite, which arrived in Rome about three years ago, involves six neighbourhood associations working in collaboration with the city.

In recent days hundreds of ladybirds, or ladybugs, were freed in the gardens of Villa Leopardi, in the Nomentana area, and Parco Mario Riva, in the Parioli district.

Massimo Proietti, president of the Amici di Villa Leopardi association, told Rome newspaper Il Messaggero that last weekend there were 200 ladybirds, a gift from Verdepieno, released on five pines in the park.

A ladybird house in Villa Leopardi. Photo Coccinella Libera Tutti.

Local municipal authorities used a mobile crane to place the ladybirds, along with little houses, high up on the trees.

Proietti said that on this occasion the ladybirds were donated but normally the volunteers purchase the creatures. 

The ladybirds cost between 30 and 80 cent each, Proietti told Il Messaggero, in contrast to the "endotherapy treatments with chemicals which costs around €300 per tree."

The various committees involved in the Coccinella Libera Tutti project have launched an online campaign to raise funds for the purchase of ladybirds for release in parks around Rome, under the slogan "One euro, one coffee, five ladybirds."

What does pine tortoise scale do to pine trees?

The highly-invasive bug feeds off the sap of trees and causes the spread of a sooty black mould, leading to extreme needle loss.

The pine fights back by generating new needles which, in turn, weakens the tree and exposes it to new attacks by the parasite. It is a vicious cycle that – if untreated – can kill the exhausted tree within two years.

How to tell if pines are affected by the parasite

Rome residents may notice unusually heavy carpets of pine needles, covered in sticky honeydew, under the city's pines.

Look up – if the tree's foliage has the appearance of being burnt then it is most likely the victim of the dreaded parasite.