Now is a good time of year to find the larvae (and indeed adults) of the two Psychoides species. Here is a photo of the portable cases made by the two species, in these cases both feeding on Hart's toungue Fern:
The first is from nr Dingestow in our neighbouring county, and shows the neat elliptical case made by Psychoides verhurella.
And this one if from my garden, showing the much messier, circular case made by Psychoided filicivora.
Feeding damage of one or other species can be found on most ferns that are fruiting and both are under-recorded, so worth looking out for.