Dark-streaked Tortrix Acleris umbrana

Formerly given the vernacular name Dark-streaked Button.

Previously a rare southern species this has increased and spread in recent years. The first Suffolk records were in the south of the county in 2018 and 2023. The 2025 record below represents the first for Norfolk.

David Norgate caught this in his garden moth trap. Although it's external appearance is fairly distinctive and I don't think anyone was in any significant doubt about its identity, it was new for Norfolk so we felt it would be prudent to confirm it genitalically and it was passed to me to examine. Compared to Varied Tortrix Acleris hastiana and Tufted Tortrix Acleris cristana the notch along the edge of the valvae is more symmetrical. All three species have a cluster of small pin-shaped cornuti in (or in this case just outside of) the aedeagus. Beyond these was a pair of elongate flattened structures which at first I thought must be additional cornuti and then wondered if in fact they were the manica. However as some photos of umbrana genitalia at the Moth Dissection website clearly show these to be inside the aedeagus vessica I think they must be cornuti. As far as I know cristana doesn't show a similar structure (I've not noticed it and can't see it in images of its genitalia); hastiana does have something similar but it seems to be a single structure with a clear dark vein through the middle.

male Dark-streaked Tortrix Acleris umbrana showing genitalia including close-up of cornuti, Toftwood (Norfolk, UK), 14th January 2025 (caught by David Norgate)