Insects from Africa munching their way across Europe

The tiny pelargonium brown is munching its way across France.

The tiny pelargonium brown is munching its way across France.

The insect, a native of South Africa, arrived in Spain by accident 10 years ago.

Its normal food is the wild pelargonium, a variety of geranium. Since its arrival in Europe, it has switched its attention to domesticated geraniums found in gardens, balconies and café terraces.

The insect has travelled halfway up France and is still heading north.

The pelargonium brown is one of many African and tropical insects to establish themselves in France in recent years after a succession of relatively warm and damp winters.

Their success was charted yesterday in a report published by a French environmental research group, Cemagref, which warned that some of the insect immigrants could eventually oust native species.

In recent years Spain has acquired a dozen new varieties of butterfly, once found only in Africa. Two of them are now spreading their wings in France. The African monarch and a rare butterfly from tropical Africa, Anatrachyntis rileyi, are already well established along the French Mediterranean coast.

The author of the report, Jacques Lhonoré, says that tropical insects have been arriving in Europe for decades, by ship, plane or on the wind. In the past 10 years, however, milder winters, possibly caused by global warming, have allowed them to survive and breed.

The report also points to other climate-driven environmental changes.

As long as it sticks to balconies and terraces, the pelargonium brown is a harmless addition to France's insect life, according to Mr Lhonoré. But he adds: "If it takes a liking to our native varieties of wild geranium, it could compete with, and even eradicate, native insects which depend upon them."