169 Mesapamea secalis (Common Rustic)

73.169 Mesapamea secalis (Common Rustic)

fw: 12-16mm; Jul-Aug; grasses (Poaceae); common throughout England, Wales and lowland Scotland.

Mesapamea secalis (Common Rustic) §7 female

ID: Forewing colour and markings extremely variable; kidney mark usually white with a white ring around it. Rounded forewing apex and smoothly curved termen distinguish it from Helotropha leucostigma (Crescent) and Amphipoea species (Ear moths) which have a pointed apex and a fairly straight termen. A.unanimis (Small Clouded Brindle) flies May-Jul, has two basal streaks, central and dorsal, the central of which is usually lacking in Mesapamea species; a crescent-shaped mark on the hindwing, better marked on the underside, is larger and broader in A.unanimis. Genital examination is required to separate M.secalis from M.didyma (Lesser Common Rustic) - see Mesapamea.
Male genitalia: clavus heavily sclerotised at the apex; cornutus broad and rounded and tethered to the vesica near its apex.
Female genitalia: swelling of posterior ductus bursae faces right (in standard ventral view with the ovipositor up).

Variation
Dissection
Male genitalia
Female genitalia

§1 Foulness, Essex; 23/07/2011; male
§2 Foulness, Essex; 12/07/2014; male; fw 13.3mm
§3 Foulness, Essex; 26/07/2014; female; fw 14.4mm
§4 Foulness, Essex; 16/08/2014; female; fw 13.2mm
§5 Foulness, Essex; 04/07/2015; male; fw 15.1mm
§6 Conwy Mountain, Caernarvonshire; 20/07/2015; female; fw 13.8mm
§7 Foulness, Essex; 01/08/2015; female; fw 15.1mm
§8 Foulness, Essex; 15/08/2015; female; fw 14.5mm
§9 Foulness, Essex; 13/08/2016; male; fw 15.5mm
All images © Chris Lewis

§10 Bampton Grange, Cumbria; 02/08/2017; male; fw 12.8mm
§11 Foulness, Essex; 15/08/2020; female; fw 14.0mm
§12 Foulness, Essex; 09/07/2022; male; fw 11.3mm
§13 Covert Woods, Kent; 24/07/2022; female; fw 14.5mm
§14 Foulness, Essex; 12/08/2023; male; fw 14.4mm