Avoid all contact if you notice this on your plants.

 

While strolling near your trees, you may have noticed strange little black, spiky caterpillars perched in colonies on the branches. At first glance, they can be surprising, even alarming. What if it's an invasion? Yet, what you're observing is the very beginning of a small miracle of nature: the arrival of the Morio butterfly, also known as the "mourning butterfly," one of the first harbingers of spring… and a discreet ally for the balance of your garden.

Eggs in clusters… and a well-organized colony

It all begins at the end of summer or the very beginning of spring. Female butterflies choose specific trees – often  willows, poplars, or elms  – to lay tiny eggs, lined up like pearls along the branches. A few days later, a mini army of black, spiny caterpillars, speckled with small white dots, appears.

Contrary to popular belief, they don't attack your  garden vegetables or flowers. Their diet is very selective: only the leaves of their host trees. The result? No threat to your plants, and no major damage to fear. Their appetite remains  moderate , and the trees recover perfectly.

After a few weeks of growth and several molts, the caterpillars take shelter to begin a spectacular metamorphosis. They form discreet chrysalides, hanging under branches, and slowly transform into butterflies with deep brown wings, edged with pale yellow and dotted with small blue spots.

Their name –  “mourning butterflies”  – evokes the color of their wings, but their presence is anything but sad: it is a  discreet symbol of renewal.

Butterflies that defy winter

One of the most remarkable features of the Mourning Cloak? It knows how to brave the cold. While most butterflies don't survive the winter, this one finds refuge in  crevices in bark or other natural shelters , hibernating. With the first sunny days, long before the first flowers bloom, it takes to the air. Its dark and elegant silhouette then becomes one of the very first signs of spring.

Three good reasons to leave them alone

Rather than trying to get rid of them, here's why you should welcome these butterflies into your home with open arms:

• An important ecological role : They participate in the pollination of certain wildflowers and feed birds and other insects, thus contributing to the natural balance of your garden.
• An educational activity for young and old : Observing their life cycle, from the tiny egg to the flight of the butterfly, is a fascinating experience to be enjoyed with children or among nature enthusiasts.
• No threat to your crops : Unlike other, more voracious caterpillars, the Morio caterpillars will not harm your tomatoes or roses. They live discreetly on their preferred trees.