Tischeriidae (Lepidoptera) leafminers new to Iran, including Tischeria caucasica on Quercus: a sibling species of T. ekebladella or a case of clinal variation?

We record three Tischeriidae species new for Iran: Coptotriche gaunacella (Duponchel, 1843) from Tehran and Mazandaran provinces, Tischeria dodonaea Stainton, 1858 from East Azarbaijan province and T. caucasica Klasiński & Stonis, 2020, previously only known from Georgia. The larvae of T. caucasica were observed mining the leaves of planted trees of Quercus infectoria G. Olivier, Q. robur Linnaeus and Q. libani G. Olivier in Peykan Shahr, Tehran province; and on native trees of Q. castaneifolia C.A.Mey. and Q. macranthera Fisch. & C.A.Mey. ex Hohen. in East Azarbaijan, Gilan and Mazandaran provinces. This species was very abundant on planted oaks in Peykan Shahr, Tehran and the infestation increased progressively in the second generation of the moth in November and December. Tischeria caucasica is very similar to European T. ekebladella (Bjerkander, 1795) in external appearance and biology, both sharing the same DNA barcode. The only diagnostic character, in the male genitalia, are the spiny appendages of the juxta. We provide a brief diagnosis and describe the larvae, leafmines and pupae for the first time. We discuss whether the observed difference in the male genitalia supports separate specific status, or is the result of clinal variation of a single species.