The Swallow Prominent is a moth

Moth

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

 from the family Notodontidae

Notodontidae

Notodontidae is a family of moths with approximately 3,500 known species. Moths of this family are found in all parts of the world, but they are most concentrated in tropical areas, especially in the New World...

.

The moth can be found in selected parts of Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, up to the Arctic Circle

Arctic Circle

The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....

. It has a forward wing length of 22–28 mm. The moth survives winter as a pupa

Pupa

A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...

 underground.

The imago

Imago

In biology, the imago is the last stage of development of an insect, after the last ecdysis of an incomplete metamorphosis, or after emergence from the pupa where the metamorphosis is complete...

 can be easily mistaken with Pheosia gnoma

Pheosia gnoma

The Lesser Swallow Prominent is a moth from the family Notodontidae.The moth can be found in selected parts of Eurasia. It has a forward wing length of 20–26 mm. The moth survives winter as a pupa underground....

. Except the latter is smaller and the white figure at the back of the forward wing is wider and shorter with Pheosia gnoma.

The host plant of the Swallow Prominent are the poplar

Poplar

Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....

, especially the aspen

Aspen

Populus section Populus, of the Populus genus, includes the aspen trees and the white poplar Populus alba. The five typical aspens are all native to cold regions with cool summers, in the north of the Northern Hemisphere, extending south at high altitudes in the mountains. The White Poplar, by...

, the willow

Willow

Willows, sallows, and osiers form the genus Salix, around 400 species of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere...

 and the birch

Birch

Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...

.