Cosmopterix schmidiella 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...

 of the Cosmopterigidae

Cosmopterigidae

Cosmopterigidae is a family of insects in the Lepidoptera order. These are small moths with narrow wings whose tiny larvae feed internally on the leaves, seeds, stems, etc of their host plants. There are about 1,500 described species...

 family. It is found from most of Great Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

 to Romania

Romania

Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...

, and from Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 through central Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

 to the Iberian Peninsula

Iberian Peninsula

The Iberian Peninsula , sometimes called Iberia, is located in the extreme southwest of Europe and includes the modern-day sovereign states of Spain, Portugal and Andorra, as well as the British Overseas Territory of Gibraltar...

. It is believed to be extinct in Britain.
The wingspan

Wingspan

The wingspan of an airplane or a bird, is the distance from one wingtip to the other wingtip. For example, the Boeing 777 has a wingspan of about ; and a Wandering Albatross caught in 1965 had a wingspan of , the official record for a living bird.The term wingspan, more technically extent, is...

 is 9-9.5 mm. Adults are on wing from August to May. Then the larva hibernates outside of the mine in a hibernaculum.

The larvae feed on Lathyrus montanus, Lathyrus niger

Lathyrus niger

Lathyrus niger, also known as black pea, blackening flat pea and black bitter vetch, is a perennial legume that is native to Europe. Its common name is reference to the blackening of the plants foliage as it dies....

, Vicia sepium

Vicia sepium

Vicia sepium or Bush Vetch is a plant species of the genus Vicia....

and Vicia pisiformis. They mine

Leaf miner

Leaf miner is a term used to describe the larvae of many different species of insect which live in and eat the leaf tissue of plants. The vast majority of leaf-mining insects are moths , sawflies and flies , though some beetles and wasps also exhibit this behavior.Like Woodboring beetles, leaf...

te leaves of their host plant. The mine has the form of a large blotch, that may occupy an entire leaflet. During feeding pauses, the larva rests in a silken resting place above the midrib. Pupation takes place outside of the mine.