Description: Wingspan 42-60mm. Adults are pale brownish-grey. The forewings have fine blackish streaks and are heavily scalloped. The hindwings are brownish-grey with a dark-coloured discal mark. Adults rest on the trunk of a tree or among ground vegetation with wings wrapped around body and palps elongated to resemble a dead leaf. The beginning of May to the end of June and again in August, suggesting a partial second generation. There are occasional records from early July.

World Distribution: Throughout much of Europe as far east as Japan.

Irish Distribution: Widespread and commonly encountered in north Armagh, parts of Down and Fermanagh. Elsewhere sporadic with few recent records in northern counties.

Ecology: Probably under recorded in a few other localities in the north where suitable habitat exsists. Adults are attracted to light in small numbers. The larvae can be found during July and again from late August to September on poplar aspen and sallow. No larvae (as far as is known) have been found in N. Ireland but I would suspect in view of the scarcity of poplar and aspen at many of its recorded localities it seems more likely that it may be using sallow as its main foodplant. It overwinters as a pupa.

Key Identification Features:

• Resting posture
• Dorsal crest
• Deeply scalloped forewings

Distribution Map from NBN: Pterostoma palpina at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Pterostoma palpina at iNaturalist World Species Observations database.