043 Adaina microdactyla

45.043 Adaina microdactyla (Hemp-agrimony Plume)

ws:13-17mm; Apr-Sep; hemp-agrimony (Eupatorium cannabinum); common in England, more so in south

Adaina microdactyla §3

ID: Although Adaina is generally recognised by its small size (ws13-17mm), there is overlap with Hellinsia carphodactyla (ws14-23mm) and H.osteodactylus (ws16-23mm). The generic distinction is based on forewing venation. According to Gielis these two genera may be separated by the extent of the apical cleft: 1/3 of forewing length in Hellinsia, 1/2 of forewing length in Adaina.
The key in Hart does not use extent of forewing cleft to separate the genera but is generally easier to use as it does not rely on forewing venation: hindwing without a scale-tooth; first forewing lobe pointed and without a discernible tornus; no specialised black scales in forewing cleft; ground colour pale; forewing lobes not noticeably thin; no tuft of dark hair on medleg tibia; proximal spur pair of hindleg of approximately equal length; ground colour not white > Adaina/Hellinsia
Forewing dusted with dark scales, costa of first forewing lobe with one or more black spots (excludes H.osteodactylus); single small black spot at base of forewing cleft > Adaina microdactyla or Hellinsia carphodactyla. These two are distinguished on the following external features - A.microdactyla given first:

Ground colour - usually pale ochreous but variable (pale brown, pale yellow, light grey) vs pale lemon yellow (when fresh)
Size - ws: 12-20mm (Hart) 13-17mm (Gielis) vs 17-24mm (Hart) 14-23mm (Gielis). So at ws < 13mm it should be A.microdactyla and >20mm it should be H.carphodactyla
Underside of forewing - evenly coloured dark brown vs proximal half darker than distal half.
Cilia of first lobe of forewing - brown vs creamy-yellow on costa, pale grey-brown on dorsum

Male Genitalia: Left valva broad and rounded with a long slender spine
Female Genitalia: Ductus seminilis very large and coiled

Variation
Dissection
Male genitalia
Female genitalia

§1 Sutton Fen, Norfolk; 22/07/2008; male; ws13.0mm, fw 5.9mm
§2 Surlingham, Norfolk; 24/07/2009; ws15.9mm, fw 7.3mm
§3 Pegwell Bay, Kent 25/05/2010; ws12.6mm, fw 5.9mm
§4 Strumpshaw Fen, Norfolk; 22/08/2012; female
§5 Folkestone Warren; 04/07/2013; male
§6 Foulden Common, Norfolk; 23/05/2016; male; fw 5.8mm; netted at dusk
§7 Foulden Common, Norfolk; 14/08/2016; female
§8 Orlestone Forest, Kent; 11/07/2018; male; fw 7.0mm
§9 Strumpshaw Fen, Norfolk; 25/05/2018
§10 Sutton Fen, Norfolk; 11/07/2022; female; fw 7.8mm
All images © Chris Lewis