Bordered Marble Endothenia marginana

This is supposed to be a common species in Norfolk but had managed to elude me for years. This one, netted during the afternoon, finally laid that to rest. The largely white hindwing made this a straightforward identification - neither males nor females of the two similar species have such clearly white hindwings (bar for the dark border).

male Bordered Marble Endothenia marginana showing hindwing, Hoe Rough (Norfolk, UK), 25th July 2023

This one was slightly tricker as the forewing had a broader dark border. The small size and largely white wing easily ruled out Teasel Marble gentianaeana but I wasn't completely certain I could eliminate Plantain Marble oblongana on external characters. Some references point to oblongana having little or no white on the top of the thorax but I can't see much difference between the species in this respect when reviewing photos on e.g. Lepiforum. Similarly the greater shading in the white band of oblongana seems to be so variable as to be of little use - at least not helpful for this one. The genitalia resolved it, the obvious notch in the middle of the uncus was clear from every angle and is lacking in oblongana.

male Bordered Marble Endothenia marginana showing hindwings and genitalia (with close-up of uncus), Wendling Beck Environment Project (Norfolk, UK), 8th September 2023

The next one was straightforward with a strongly white (dark-bordered) hindwing.

male Bordered Marble Endothenia marginana showing hindwing, Wendling Beck Environment Project (Norfolk, UK), 15th May 2024