We’ve embarked on a journey at Osney Lock Hydro this year discovering some of the moths present at the site.

Most moths fly at night, so we use a light trap to attract and capture them. The moths are unharmed by this and are released after recording. We checked for moths twice last year and have used the light trap five times this year. Across all seven sessions we recorded 55 moths from 32 species.

The moths we see are all common and mostly from the two largest families of macro moths. They can be astonishingly beautiful. The gallery below shows some of the moths we’ve recorded this year.

Perhaps not surprisingly, the plants growing at the hydro and in the surrounding area correlate strongly with those used by the moth species we’re seeing, both the adults and their caterpillars. Many adult moths feed on nectar from flowers and are important pollinators so the flower border at the hydro is providing a food source. Some also feed on ivy flowers and ripe blackberries.

The caterpillars use a variety of food plants depending on the species. These include oak, hazel, hawthorn and willow, various grasses, plus herbaceous plants like docks, plantains, sorrel, dandelions and buttercups. Most of these plants are present at the hydro site and our management of the garden focuses on encouraging them.

We plan additional recording next year to build a more complete picture of the moth population in the area. We post our records on iRecord where they are checked and verified by experts. Collecting data on moths and other insects is useful for scientists trying to understand what’s happening to our biodiversity nationally.