Bordered Marble Endothenia marginana

This is a common species in Norfolk but somehow it 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 following year I caught several more.

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

male Bordered Marble Endothenia marginana showing hindwing, Wendling Beck Environment Project (Norfolk, UK), 14th July 2024

3x male Bordered Marbles Endothenia marginana showing hindwings, Wendling Beck Environment Project (Norfolk, UK), 16th July 2024

2x male Bordered Marbles Endothenia marginana, Wendling Beck Environment Project (Norfolk, UK), 17th September 2024

4x male Bordered Marbles Endothenia marginana, Wendling Beck Environment Project (Norfolk, UK), 23rd August 2024

It wasn't until 2025 that I finally added this species to my garden list.

male Bordered Marble Endothenia marginana showing hindwing, North Elmham (Norfolk, UK), 1st May 2025

The two photos of the live adult were taken with different cameras and the first has come out looking much browner than the second. I think the true colours were probably somewhere in between. The hindwings were probably sufficient to clinch the ID but they weren't as clear as they can be so I checked the genitalia to make quite sure.

male Bordered Marble Endothenia marginana showing hindwing, North Elmham (Norfolk, UK), 1st May 2025

I had previously identified this one for Laura. Again I wasn't totally certain from the hindwings so confirmed by checking the genitalia. This species is the only one of the three similar species to have a strongly notched uncus.

male Bordered Marble Endothenia marginana showing hindwing and genitalia (including close-up of uncus), Lower Hellesdon (Norfolk, UK), 16th September 2021 - caught by Laura King