036 Acronicta alni (Alder Moth)

73.036 Acronicta (Jocheaera) alni (Alder Moth)

fw: 16-19mm (Waring & Townsend), ws: 35-42mm (MBGBI10); May-Jun; various broadleaved trees; local in broadleaved woodland in England, Wales and SW.Scotland.

Acronicta alni (Alder Moth) §2 female

ID: Forewing ground colour varies from light to dark grey; median fascia diffuse, black; oval usually distinct and outlined black, often with a short black streak distal to it which may crossed to resemble a ♀ symbol; kidney indeterminate; basal streak black, bold and long, reaching median fascia; tornal streak also black bold and long, overlapping the basal streak on its costal side; subterminal line pale, diffuse and cut by a short black streak from the termen slightly costal to its mid-point and sometimes by a second short black streak from the termen near the apex; postmedian line pale, bordered black on its terminal side, usually with a pale circle of ground colour between it and the median fascia in the costal half of the wing (cf A.megacephala (Poplar Grey)), broadly obscured by the tornal streak and reappearing as a whitish mark on the dorsum (cf A.rumicis (Knot Grass)); subbasal line usually discernible as a short pale line between the basal streak towards the costa; terminal cilia chequered; pale examples show 4 white spots on the costa between the subterminal line and median fascia. Hindwing white; veins marked blackish distally; variable blackish terminal fascia; cilia chequered. Thorax often contrastingly white or whitish (cf Craniophora ligustri (Coronet)) but may be concolorous with forewing ground colour. Vertex and frons concolorous with thorax; a broad black band in front of eye and on S2 of labial palps.

Variation
Dissection
Male genitalia
Female genitalia

§1 Cyffdy Farm, Gwynedd; 22/06/2010; male; fw 19.3mm
§2 Newgale, Pembrokeshire; 18/05/2011; female; fw 20.5mm
§3 Strumpshaw Fen, Norfolk; 29/05/2012
§4 Strumpshaw Fen, Norfolk; 16/05/2017; male; fw 16.7mm
§5 Strumpshaw Fen, Norfolk; 25/05/2018
§6 Orlestone Forest, Kent; 18/05/2020
§7 Orlestone Forest, Kent; 18/05/2020
§8 ??; ??/??/2021; male; fw 17.7mm
§9 New Forest, Hampshire; 30/05/2023; female; fw 18.2mm
All images © Chris Lewis