any of a group of moths in the family Zygaenidae (order Lepidoptera) that are closely related to the burnet moths. The adult forester moth has shining green forewings with a span of about 3 cm (1.2 inches), translucent, dark hind wings, and an iridescent body. The insect's green appearance at rest may have given rise to the common name forester. Young larvae mine in leaves of various herbaceous plants and feed within the tissues. Larger larvae stay under leaves and spin a tough, white, silken cocoon in which to pupate. Cocoons are often constructed on a grass stem. Adult foresters are weak fliers and take to the wing only in sunshine.