Langmaid's Yellow Underwing
This species of moth (Noctua janthina) was first described as recently as 1991, having been separated from the exceedingly similar Lesser Broad-bordered Yellow Underwing (Noctua janthe). The first British record came shortly afterwards, with more quickly following, mainly along the south and south-east coasts. It has slowly spread further, with a few Surrey records having been made, but up until this morning I had failed to detect it at Banstead.
Any early janthe (especially a dark one) is worth checking for janthina, so when I spied a candidate in the MV this morning I gave it a thorough examination. It ticked all the boxes - an isolated yellow blob on the upper hindwing (above) and the underside of the forewing exhibiting no pale finger-like projections into the dark base colour (below). I was grateful that Sean Clancy and Nigel Jarman were able to confirm my suspicions. So welcome to Banstead janthina!