Could the fly in the pictures below be a Chloropidae spec., possibly Trachysiphonella scutellatus? Seen 04-06-2022 on a curled Alnus leaf in the SE of the Netherlands. Thank you for your help.
Chloropidae: Thaumatomyia notata (Meigen, 1830) is correct. Several rows of setulae on the ocellar triangel; approximate apical scutellar bristle are typical for Thaumatomyia. Many posts in diptera.info .