Larva: (description Ian F. Smith):Foodplants:Herbaceous plants; Centaurea, Cirsium, Heracleum, Angelica, Daucus, Tussilago, Plantago, Scabiosa, Caltha, Filipendula, Artemisia, Stachys, Trifolium, Rumex, Montia etc. Grasses; Phragmites, Agropyron, Phleum etc.. Occasionally trees; Quercus, Fagus, Rosa.
Early instar in spun leaves in August and September, diapause off plant October to March, late instar in spun leaves April to early June. A pod with frass at the lower end is sown from a single leaf on large leaved plants, such as Centaurea.
Length:Final instar 17 mm or more.
Head:Brown ochre with variable amounts of black. Prothoracic shield:Shiny black, with whitish broad anterior margin and medial line tinted by brown of head beneath.
Thoracic legs:Black.
Body:Black, sometimes with greenish or brownish hue.
Spiracles:Black.
Pinacula:White with black spot at base of seta.
Setae:Translucent pale straw.
Anal plate:Shiny black.
Prolegs:Black with white planta and black crochets.
Similar species A. paleana is a common polyphage, but in moorland habitats A. viburnana is more likely. Check the thoracic leg colour, prothoracic shield and anal plate.