Lymantria monacha, commonly known as the nun moth, is a species of moth belonging to the family Erebidae. It is primarily found in Europe and parts of Asia, where it inhabits forests and woodlands. The adult moths are characterized by their brownish-gray wings, which can have a distinctive pattern, and a wingspan of about 30 to 40 millimeters. The larvae, or caterpillars, of Lymantria monacha are known for their voracious appetite, feeding on the leaves of various trees, including pine and birch. This feeding behavior can lead to significant defoliation, making the nun moth a pest in some regions. Effective management strategies are essential to control their populations and minimize damage to forests.