This is an interesting little moth to look for over the next few weeks. Its one of the so called "microlepidoptera" which as the name suggests are usually very small but nevertheless they can be very colourful as adults. My own personal favorite way of looking for moths is to try and find the larval stages on their food plants rather the usual practice of running a light or moth trap to attract the adults.
This particular species is one of the so called “leaf miners” which are a vary varied group of moths that develop in their larval stages in a leaf or grass blade before pupating and emerging as an adult moth when they have completed their devlopement. You can often identify these moths most easily from the type of mine they make in their chosen food plant. The adults are often dull little moths that look very much like each other. The mines can be found at all times of the year when the food plant is around either as active mines or vacated ones when the larvae leaves the mine to pupate and emerge.
The species shown can be found now as it’s starting to become active and feed again after resting over winter. Look over patches of Hart’s tongue ferns on the older leaves for small brown blotches on the leaf surface and then check underneath for the small cases made of fern spores in which the larvae live and feed. There is one other Psychoides species that feeds on Harts Tongue ferns and males a similar case, this species is called Psychoides filicivora.
Images of both species can be seen at these two excellant websites
http://www.leafmines.co.uk/
http://www.ukmoths.org.uk/
