Elachista bidens 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 Elachistidae

Elachistidae

| image = Elachista rufocinerea 2.jpg| image_width = 240px| image_caption = Adult Elachista rufocinerea,demonstrating its tiny size versus an aphid and a spider mite | regnum = Animalia| phylum = Arthropoda| classis = Insecta...

 family. It is found in Western Australia

Western Australia

Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...

.

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 10.6 mm for males and 12.7 mm for females. The forewings are blue. The hindwings are grey.

The larvae feed on Lepidosperma tuberculatum. 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...

the leaves of their host plant. The mine is straight, whitish and reaches a length of about 200 mm. Pupation takes place outside of the mine on a leaf of the host plant.