On the Wildside: Is this our most common big moth?

This is the ‘large yellow underwing’, one of the so-called ‘fat-bodied’ moths or noctuids (around 25,000 species known to science and still counting!) This is one of the most common and familiar of our moths and in some years highly migratory with large numbers arriving suddenly in areas across its range. Along with a cousin, the ‘silver-Y’, this moth can appear in gardens and parks in huge numbers if the weather is hot, sultry, humid, and still, and in the evening darkness, every flower seems surrounded by several big moths. The larvae or caterpillars feed on almost any herbaceous plant, but particularly docks, marigolds, foxgloves, and grasses such as meadow-grass. They then like to pupate in dry, secure spots like the leaf litter at the bottom of a hedgerow. As children we used to search these out with their bright, shiny brown, wriggling, pupal cases that we carefully placed in a jam-jar with some dead leaves to keep them safe. However, the excitement often turned to disappointment because when they hatched out it was often not the pristine moth we were hoping for, but a parasitic wasp that had been laid into the unsuspecting caterpillar. The poor thing had been eaten alive whilst going through the conversion process known as metamorphosis.

Despite their somewhat fraught lifestyle, these moths still do well, and Paul Ardron and Jan Turner may get over seventy individuals in their moth trap below Meersbrook Park, Sheffield, in August. Like many of the moths there are numerous closely related species and varieties, and some are still only now being recognised. The large yellow underwing has more subdued upper wings and they are incredibly variable from pale fawn to dark brown and with dots and other marks, but generally regarded as one species. Others, however, include lunar yellow underwing, broad-bordered yellow underwing, lesser broad-bordered yellow underwing, least yellow underwing, and lesser yellow underwing, I think you get the picture!

Professor Ian D. Rotherham, researcher, writer & broadcaster on wildlife & environmental issues, is contactable on [email protected]; follow Ian’s blog (https://ianswalkonthewildside.wordpress.com/) and Twitter @IanThewildside