Powdered Quakers and a dead first for Norfolk

Still cold and not many moths... just 7 on Tuesday night (Brindled Beauty, 2 Powdered Quakers and 4 Hebrew Characters) and 6 last night (Clouded Drab and 5 Hebrew Characters). 

Powdered Quaker, North Elmham, 28th April

Dave netted some moths at Kelling Heath on Tuesday and sent me some photos.  One was one of the Birch-feeding Eriocraniids, I thought probably Large Birch Purple Eriocrania sangii.  It had died by the time he brought it round to me but at least that meant I could have a good look at it.  According to the keys the two commoner Birch feeders, sangii and semipurpurella, have narrow hair-like scales in the discal area of the hindwing, unlike the other species that have broader scales.  They also have antennae slightly longer than half the length of the forewing.  This individual had antennae shorter than half the length of the forewing but the scales on the hindwing looked pretty narrow to me.  Hair-like though, I wasn't sure, so looked for photos that show the difference.  Chris Lewis's British Lepidoptera site shows a close-up photo of each (comparing hair-like scales of sangii with broader scales of unimaculella).  Through the microscope Dave's moth's hindwing looked like Chris's image of unimaculella.  So it couldn't be sangii or semipurpurella, and that immediately made it more interesting.

Continuing through the key in MOGBI I eliminated cicatricella (= haworthii) and chrysolepidella as the forewing wasn't elongate which left salopiella and sparrmannella.  The latter has mixed fuscous and whitish hairs on the head and a golden forewing strongly reticulated with purple whereas salopiella, and Dave's moth, has pale yellow hairs on the head and forewing mostly suffused purple.  As a final double check in case I'd misjudged the hindwing or forewing shape I checked images of the other species, none of which seem to share the pale yellow head hairs.  Other images of salopiella were good matches, so I think the ID is safe, Small Birch Purple Eriocrania salopiella.  It's not a hugely rare moth in Norfolk, but is usually only recorded from leafmines or larvae.  Indeed looking through the 13 previous county records I see they're ALL larvae or leafmines, which makes Dave's the first adult to be recorded in Norfolk!

Here is a pic of the hindwing (compare with Chris's image comparison), a close-up of the head showing the pale yellow hairs and one of the whole moth.

Small Birch Purple Eriocrania salopiella, collected from Kelling Heath by DN, 28th April

***Update***: this is now gen detted and considered to be correctly identified, along with a second indivdual caught a few days later - see this blog post.