A December Moth is a brown and fluffy medium-sized insect. As their name suggests, the main period of activity is during December; however, they can be active from as early as October. The caterpillars are most prevalent in spring, and during this time they feed on a large variety of deciduous trees; specifically oaks, birches, elms, hawthorns, blackthorn and sallows. They're attracted to woodland habitats but can also become established in a garden setting. These moths are attracted to light, so you may see them flying about near garden lamps.
the caterpillars of this moth may defoliate the host plant.
These moths serve as an excellent snack for animals like hedgehogs, bats and birds.
When at rest, the adult moths wings appear grey with a distinctive cream stripe spanning the wings. They possess thick, brown furry collars with additional light brown hairs covering the face. The males are much smaller than females (3cm); where a females wings will reach as far as 4.5cm when opened. They possess large, comb-like antennae. These are modified to detect a females scent that's miles away!
Caterpillars may defoliate the food plant.
Widespread across the UK.
Defoliation is more prominent where trees are younger and less established. If you see these caterpillars on smaller plants and trees, it's probably best to move them on more established plants. It's extremely rare for a plant to become severely defoliated as a direct result of these caterpillars.
It's not advised to remove these insects from the environment due to the minor risks they pose to garden plants.