Rome’s iconic Mediterranean stone pines, a defining feature of the city’s skyline, are under threat. The green crowns are darkening, and hundreds have fallen. A small reddish-brown insect from the Americas is poisoning them. What began as a local problem has grown into a crisis for Rome’s urban canopy.
Agronomist Sara Sacerdote describes the situation with blunt clarity. “The entire region of Rome is affected. This is a serious situation,” he says. The troubling news isn’t new, but it has intensified. Toumella parvicornis, also known as the tortoise cochineal, arrived in Italy about seven years ago and began devastating pines in southern regions. Naples and Campania could have been among the first hit after movement from the Caribbean. Sacerdote notes that this pest moved inland after establishing from cooler Canadian climates into warmer Italian landscapes.
Since then, the fight has been long with few clear victories. The Mediterranean climate helps the pest, and there are few natural predators in Italy to keep it in check. The tortoise mealybug travels slowly along the coast, reaching Rome where it appeared in the city’s southern districts in 2018.
A fight without victory yet
The Vatican has a stake in protecting Rome’s trees. It has already supported numerous trees with a direct remedy that has emerged so far. Endotherapy is used to treat affected trees. This method involves drilling small holes about 30 centimeters apart and injecting an insecticide called abamectin into the tree’s vascular system. The pesticide travels with the sap to reach the parasite and destroy it. Yet the problem persists: while the treatment buys time, it is not a cure. The effects of abamectin fade after roughly three months, after which the parasite can return, especially if the tree is already badly damaged.
Endotherapy also comes with cost and time constraints. Experts estimate around 50 euros per tree, and the process is slow because each tree requires multiple injections. As a result, researchers are pursuing alternate experiments with limited results to date. Some universities are exploring the use of ladybugs to attack mealybugs, and there is even consideration of importing natural predators from the pest’s origin to counter Toumella parvicornis. A definitive solution remains elusive.
situation Rome faces a race against time. Sacerdote emphasizes that the Pinus pinea has defined the capital’s landscape since the era of the Etruscans, with extensive planting continuing into the 19th century. In the 1940s, Mussolini promoted these trees as a symbol of Italy, even renaming the group of trees to emphasize their Italian identity. The iconic pine became a national emblem, a symbol reflected in civic pride as well as urban scenery.
A Roman symbol
Even before this symbolism, the pines held a historical role. In 1924, the famous symphonic poem Roman Pines by the Italian composer Ottorino Respighi celebrated their presence across the city in daylight. The pines have also served as cinematic settings, appearing in works by Rome’s Fellini and in Paolo Sorrentino’s contemporary film The Great Beauty, further embedding them in Italian cultural imagination.
Franco Milito, a Roman agricultural engineer, has long admired these trees. He notes that the pines are a defining feature of Rome’s skyline and would be profoundly missed if their decline continued. He has experimented with introducing fungi that penetrate branches and trunks, forming a dark soot that can hinder photosynthesis by altering the leaf surface, and he monitors the impact of this change on the city’s visual identity. Milito remains vigilant about maintaining a healthy urban canopy even as sugar-rich exudates from infested trees pose additional challenges.
The situation underscores the broader environmental drama of our era. The conversation about climate and ecosystem balance grows louder as the planet faces continued disturbances. In Rome, Antonello Venditti, one of the city’s most beloved singer-songwriters, once echoed the resilience of the pines with the lyric, “Like the pines of Rome, life does not break us.” The current reality invites a reassessment of that sentiment.