Cosmopterix orichalcea 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 known from most 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...

 (except the Balkan Peninsula) east to 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...

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

The larvae feed on Anthoxanthum odoratum

Anthoxanthum odoratum

-Introduction:Anthoxanthum odoratum, known as sweet vernal grass, holy grass, vanilla grass or buffalo grass, is a short-lived grass found wild in acidic grassland in Eurasia. It is also grown as a lawn grass and a house plant, due to its sweet scent, and can also be found on unimproved pastures...

, Festuca arundinacea

Festuca arundinacea

Festuca arundinacea is a species of fescue commonly known as Tall fescue. It is a cool-season perennial C3 species of bunchgrass native to Europe. It is an important forage grass throughout Europe, and many cultivars have been used in agriculture...

, Hierochloe odorata, Milium

Milium

Milium can refer to* Milium , a genus of grasses* the singular form of Milia, a milk spot...

species, Phalaris arundinacea and Phragmites australis. 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. They prefer the lower leaves. The mine has the form of an elongate, rather irregular blotch. Most frass

Frass

Frass is the fine powdery material phytophagous insects pass as waste after digesting plant parts. It causes plants to excrete chitinase due to high chitin levels, it is a natural bloom stimulant, and has high nutrient levels. Frass is known to have abundant amoeba, beneficial bacteria, and fungi...

is ejected, but the remaining frass is concentrated in a few heaps. A single larva makes several mines. Pupation takes place outside of the mine.