The beautiful Clifden Nonpareil (Catocala fraxini), or Blue Underwing as it is also known, is an immigrant to Sussex and suspected resident since 2001 or 2005. It is generally only found singly and is attracted to sugar, usually at dusk, and occasionally to MV light. Immigrants appear in a wide range of habitats, chiefly in the south of the county; while residents prefer wooded landscapes in the far east. During the middle part of the 20th century it was resident in certain parts of Kent and Norfolk. C. fraxini is single-brooded; flying mainly from mid August to mid October. The larvae, which can be as much as 75mm long, feed mainly on aspen (Populus tremulosa). It overwinters as an egg.
Nowadays, only a handful are recorded per year, mainly from the south and south-east of England; September being the most likely month. On 17th October 2011, my good friend Alec Harmer, took a gravid female at MV light in his garden on the edge of the New Forest in Hampshire. Her forewings were in reasonable condition, but her hindwings were badly torn. She laid 21 eggs and sadly died within a few days of capture. One of her offspring has subsequently laid over 563 ova and it is from her successors that the following larvae were reared. They were photographed on 4th July 2012.
Long may her descendants live on ...