Dark Hornbeam Leaf-miner Phyllonorycter esperella

Formerly given the vernacular name Dark Hornbeam Midget.

This worn Phyllonorycter didn't give much away about its ID until I dissected it. It was new for the garden and the first adult I've ever identified anywhere.

male Dark Hornbeam Leaf-miner Phyllonorycter esperella showing genitalia, North Elmham (Norfolk, UK), 18th July 2022

This one was a bit better. The way that the costal strigula extends slightly along the costa seems to be unusual among the similar Phyllonorycter but is shared by Phyllonorycter coryli.

male Dark Hornbeam Leaf-miner Phyllonorycter esperella showing genitalia, Wendling Beck Environment Project (Norfolk, UK), 18th April 2024

The mines are in Hornbeam and they don't seem to be as hard to find as the adults.

Dark Hornbeam Leaf-miner Phyllonorycter esperella leafmine and larva, North Elmham Chapel (Norfolk, UK), 16th September 2020

This one was found on the same group of Hornbeams but the larva differed in appearance, lacking the distinct dark dorsal plates, prompting me to seek confirmation that I had identified them both correctly. Thanks to James Emerson for pointing me to the bladmineerders.nl website which explains that this species has two distinct larval stages, an early sap-feeding stage (above) and then a plainer tissue-feeding stage (below).

Dark Hornbeam Leaf-miner Phyllonorycter esperella leafmine and larva, North Elmham Chapel (Norfolk, UK), 16th September 2020

Dark Hornbeam Leaf-miner Phyllonorycter esperella leafmine, North Elmham Chapel (Norfolk, UK), 30th September 2019.