About Aethalura punctulata (Denis & Schiffermüller), 1775
Aethalura punctulata, commonly known as the grey birch, is a moth species belonging to the family Geometridae. Its distribution ranges across Europe, extending eastward to western Siberia and the Caucasus. This species favors sparse alder-ash floodplain forests located in moist to wet sites. While it only occurs locally across Central Europe, it is typically common within these suitable habitats. It can be found from low plains up to middle mountain regions, reaching elevations as high as 1,600 meters in the Alps. The wingspan of this moth measures 30 to 35 millimeters. The upperside of the forewings ranges in color from ash gray to light brownish gray. This species has both darkened and light color forms, with variable banding patterns. Three distinct black crossbars are strongly developed and usually reach the front edge of the wing. Due to this variability in color and wing markings, multiple forms of Aethalura punctulata have been formally described. Form f. trilineata Bruckova, 1945 has three clear cross-lines. Form f. marginata Lempke, 1953 has darkened clouding on both the front and rear wings. Form f. albescens Prout, 1915 has an almost uniformly whitish ground color across the wings. Form f. intermedia Lempke, 1953 has dark grey wings with clear markings. Form f. cinerea Leraut, 2002 has ash grey wings with clear markings. Form f. obscuraria Paux, 1901 has uniformly black-grey wings. Form f. costijuncta Lempke, 1970 has a wide black band along the front edge of the front wing. Form f. anastomosaria Lempke, 1970 has complete first and second cross lines on the front wing. The larvae of Aethalura punctulata can be brownish, greenish, greenish-grey, or violet-brown. The longitudinal lines and segment incisions are typically yellowish or whitish, and often bear enlarged spots. Longitudinal lines are often interrupted, or broken into elongated points. The pupa is reddish-brown to dark reddish-brown, with a blunt-conical cremaster. Adult moths fly from March to July, with flight timing varying by location. Caterpillars of this species feed on birch.
