Alder Sawfly (Cimbex connatus) confirmation needed

Alder Sawfly (Cimbex connatus) confirmation needed

Observation - Alder Sawfly (Cimbex connatus) confirmation needed - UK and Ireland. Description: Seen crawling up tree trunk on the bank of the River Otter near Otterton. It was so big at 1st glan

Seen crawling up tree trunk on the bank of the River Otter near Otterton.
It was so big at 1st glance i thought it was a hornet