How do processionary caterpillars change during their life cycle on Mallorca?

Along the pine-lined slopes of the Serra de Tramuntana, processionary caterpillars reveal their remarkable transformation throughout the seasons. Their life begins in late winter when the adult moths lay creamy white egg clusters on the needles of Aleppo pines scattered near towns like Sóller and Valldemossa. When the eggs hatch in early spring, the tiny caterpillars are barely visible, cloaked in soft hairs and displaying muted, striped patterns that help them blend into their piney surroundings.

As they mature, their bodies lengthen to several centimeters, becoming more robust and covered with long, stinging hairs that ward off potential predators—an adaptation that visitors hiking trails above Deià or driving along the Ma-10 often learn to respect. These larvae are famous for their unique habit of moving head-to-tail in long 'processions,' a behavior clearly observable in shaded woodlands during their active months.

Later, the caterpillars secure themselves in silk cocoons nestled within pine tree branches or the fragrant understory near Cala Mondragó. Inside these safespaces, they pupate, gradually transforming into adult moths. While these moths adopt less vivid coloration, blending into bark and leaves, their earlier stages remain a striking feature of the island’s natural cycle. Understanding this process enriches nature walks, especially in the peaceful groves around Pollensa or near the pristine coastal coves of Formentor.