Chris,

A recent paper reviewing the Heterarthrus species sawfly leaf miners found that leaf mines previously identified as Heterarthrus aceris were in fact a misidentification and should be renamed Heterarthrus fiora.

Reference: Liston, A, Mutanen, M, Viitasaari (2019) - On the taxonomy of Heterarthrus (Hymenoptera, Tenthredinidae), with a review of the West Palaearctic species, Journal of Hymenoptera Research, 72, 83-126

Steve