73.342 Noctua pronuba (Large Yellow Underwing)
fw: 21-26mm; Jun-Nov; various herbaceous plants and grasses; common resident and migrant throughout GB.
ID: Generally recognisable in both sexes from size, elongate shape and a small black dash on the costa close to the forewing apex. Ground colour very variable - male: pale reddish-brown, through dark reddish-brown to blackish-brown, with or without a pale costal streak and variably marbled; female: uniform pale brown through reddish brown to brownish-grey, variably flecked with darker scales; oval and kidney mark obscure to well-marked and pale; no distinct cross-lines; hindwing bright yellow with a narrow black subterminal fascia. N.orbona (Lunar Yellow Underwing) also shows the costal dash and a narrow black hindwing subterminal fascia, but is smaller (fw 17-20mm) and shows a central black hindwing crescent. All other Noctua species lack the costal dash.
All images © Chris Lewis