Though this post is entitled Gypsonoma species (and that’s how I recorded my find), according to one of my friendly local experts, the mines shown here are very likely to be Gypsonoma oppressana as that species usually mines communally, with up to three mines on a leaf. The other Gypsonoma species possibility that also uses Poplar as a larval food plant (though mines other tree leaves as well) is G. dealbana but its larvae are usually solitary miners and, if you happen to spot them, are whitish rather than the brown colour of G. oppressana. You may just be able to make out in my photos the frass-covered silken tubes these larvae create to hide in.

I was a little late in the season looking for this species but my expert tells me I won’t have to wait till next autumn to restart my search for more Gypsonoma oppressana larvae. In the spring, when the larvae wake up, they feed inside Poplar leaf buds, but they still live within their pooh-covered tubes and these can be spotted poking out from the holes they make in the leaf buds.

The adult Gypsonoma oppressana is a gorgeous little moth, with subtle patterning in shades of grey, brown, white and cinnamon, which you can see on the UK Moths website.