Hi there experts ! Wondered if you can help. Largish moth found, unfortunately no photo as I did not want to hurt it. Found in garden in North Yorkshire (seaside location) mthis month. Length about 35mm dark brown arrow shaped wings with slight indication of 2 small black spots, one on each wing cover. The giveaway was when the moth flew. Bright yellow/orange underwing with black flash at base. Have tried all the 'common moth' guides with no success. Many thanks in anticipation. Fileyman.