26th September 2022, I was near John Luke Bridge, New Forge, Belfast. Off on my regular morning jaunt with our dog, Milou, we ended up on the edge of Clement Wilson Park at the John Luke Bridge crossing the River Lagan. There are three Etainia species in Great Britain, E. sericopeza (feeds on Norway Maple) which I had found earlier in 2022 as New to Ireland, E. louisella  (Field Maple) and E. decentella (Sycamore). I have been searching for louisella without any luck but at the bridge there was an opportunity to search for the much harder to find (described as near mythical by one of the leaf mine gurus!) decentella. It is thought that it is hard to find as it feeds on samaras high in the canopy, in fact unusually the adult is more frequently encountered than the mine.
The bridge offers some height and a large sycamore branch with samaras overhung the path. I almost immediately found a single mine. Despite a thorough search of the samaras I could reach I found no others.
To my eyes the mine is shorter and stockier than that formed by sericopeza. On line I could only find a very small number of images so I posted on the Leafmines Facebook page just to get confirmation which was quickly forthcoming.
Since this discovery two records of adults have come to light, one in Wicklow in 2022 and a much older record from Kildare in 2009. So this represents the first Irish record of the hard to find mine.
Dave Allen 16/02/23