Posted on May 25, 2022
I saw this unusual moth resting on a wall as I walked around Greenwood House. I have never seen one before and it took me a while to identify it. My first thought was that it was a melanistic form of the Peppered Moth (Biston betularia) which is well known because early descriptions of the form were considered an adaption to living on the grimier surfaces of industrial locations. In fact, the moth at Greenwood is a male Muslin Moth (Diaphora or Cycnia mendica). The male is dark with wonderful feathered antennae (bipectinate I think they are called). This particular specimen has a brown to almost black coloration with a few almost indiscernible black spots on the wings. The thorax looks as if it is covered in deep brown fur with yellower hairs underneath . There are not many British moths this dark. [The female Muslin Moth, in contrast, is white with more spots on her wings, and the antennae are long and slender].
The caterpillars are said to feed in July, sometimes earlier, and August, and seem to thrive on the foliage of many kinds of low growing plants, such as dandelion, dock, plantain, chickweed, and also the leaves of birch and rose. In the village right now there are lots of low growing plants of this kind on which the female moth can lay eggs because of the “no mow May” campaign that has led to some wilder patches of ground being left untouched for the time being. Unfortunately, most of these temporarily thriving habitats will be cut down before the caterpillars emerge.