Springtime leaf-mining brings results...

Spring is the time to check birches for Eriocrania leaf-mines, as well as looking for mines on other plants. Yesterday morning (2/5), during intermittent drizzle, I visited an old mine site at Cynheidre, just north of Llanelli.
The most satisfying mine found was that of Eriocrania cicatricella, something I`d been on the look-out for in the past, but failed to find. It is reasonably distinctive in that there are 2-4 larvae per mine, rather than the usual singleton, but you need to check the larvae afterwards to be sure.

Top: birch leaf showing `shadows` of three larvae in bottom part; also note the greenish hue to the eaten part of leaf. The black `squiggles` are frass (droppings).
Bottom: one of the larvae - note swollen thoracic segments towards the head.

Presumably new to the county, as not listed in Sam`s 2016 list of Carmarthenshire species.
Thanks to Sam for confirming the i/d.
The website `UK leaf mines` is always very helpful. I go first to the plant section and click on the (scientific) plant name to see the options.