Here are two great photos by Friends of Crossness Nature Reserve’s Mike Robinson, taken on Erith Marshes at Crossness recently, showing a male Brown Argus butterfly in excellent detail. It can be hard to tell the Brown Argus apart from an all-brown female Common Blue, and a good guide to how to do it is here:
http://www.glaucus.org.uk/BflyBlues03.html
Note in particular the prominent forewing elongated black spot and the lack of white in the hindwing lunules in Mike’s wings-open photo, and the pair of white-ringed black spots making a figure of 8/’colon’ pattern at the centre of the hindwing underside’s leading edge in his wings-closed picture.
Brown Argus at Crossness, wings open. (Photo: Mike Robinson)
Brown Argus with wings closed. Erith Marshes at Crossness. (Photo: Mike Robinson).
