Phyllonorycter tristrigella – New to Ireland!
15.078 Phyllonorycter tristrigella (Haworth, 1828)
16th August 2022, Minnowburn, Belfast. Off on my regular morning jaunt with our dog, Milou we ended up by the Minnowburn stream where there is good tree cover including a couple of Wych Elms Ulmus glabra in the under-storey. I initially noticed a gallery mine (turned out to be Stigmella lemniscella – yellow larva present) but then to my astonishment a tentiform mine of a Phyllonorycter, something I had never previously seen on Wych Elm, caught my eye. There are only two options in GB noted on the leaf mining websites, P. tristrigella and P. schreberella. There are no cross-over species listed i.e. species on the “wrong” host. A quick run through the keys and checking images quickly confirmed the mine to be P tristrigella. P. schreberella forms an oval tent/blotch, often crossing veins, it is uncommon on Wych Elm and has a very southern distribution in GB. Tristrigella mines lie between veins forming a strongly contracted tube running from mid-rib to leaf edge, obvious in the attached images. There are a few strong folds on this mine which hard to capture in the image as the mine is so puckered causing them to merge. Frass was tightly packed in bottom corner of the mine. The mine was vacated. Amazingly following this discovery Eamonn O’Donnell found a long vacated mine, also on Wych Elm, in Dublin the following day! Thanks again to CEDaR and the Environmental Recorders Group small grant. To date I have found it nowhere else despite searching.
Dave Allen 22/08/22