012 Argyresthia goedartella

ARGYRESTHIIDAE

20.012 Argyresthia (Argyresthia) goedartella (Brassy W)

ws: 10-12mm; Jun-Sep; birch (Betula spp), alder (Alnus glutinosa); common throughout GB

Argyresthia goedartella §5

ID: A - forewing unicolorous shining bronzy gold; thorax not white > A.brockeella/goedartella. These two are separated in MBGBI3 on basis that in A.brockeella the forewing is deep bronzy gold, while in A.goedartella it is yellowish gold. I have found this to be an unreliable distinction. Often on apparently unicolourous specimens a hint of the standard forewing pattern can be seen on close inspection, but completely plain specimens will need genital dissection.
B - forewing not unicolorous, basal third not entirely white, white on dorsum interrupted before 1/3, without 3 white transverse fasciae, with dark fascia near base; thorax and tegulae metallic brassy, central (dark) fascia separated from the terminal (dark) markings by an oblique white fascia (which may be suffused with ground colour) > A goedartella

Variation
Dissection
Male genitalia
Female genitalia

§1 Newborough, Anglesey; 03/08/2007
§2 Thursley Common, Surrey; 16/06/2008; fw 5.2mm
§3 Surlingham, Norfolk; 24/07/2009; male
§4 Westcliff-on-sea, Essex; 20/07/2010
§5 Kinlochleven, Argyll; 05/07/2011
§6 Kinlochleven, Argyll; 05/07/2011
§7 Arne, Dorset; 05/07/2016
§8 Duddon Moss, Cumbria; 22/07/2016; netted by day
§9 Seathwaite, Cumbria; 23/07/2016
All images © Chris Lewis

§10 Strumpshaw Fen. Norfolk; 16/09/2018; female; fw 5.3mm
§11 Orlestone Forest, Kent; 24/06/2020; male; fw 4.8mm
§12 St Mary's, Isles of Scilly; 22/08/2022; male; fw 5.2mm; specimen of Mick Scott
§13 St Mary's, Isles of Scilly; 26/08/2023; female; fw 5.0mm; specimen of Mick Scott
§14 Inveruglas, Inverness-shire; 31/07/2023