Phytomyza angelicae

Phytomyza angelicae

Observation - Phytomyza angelicae. Description: This looks like a leafmine in the upper surface of Wild Angelica (Angelica sylvestris). The leaf eventually breaks up (photo 3). Can anyone tell me what caused it, please? Edit: Changed to match darob57's ID. Many thanks.

This looks like a leafmine in the upper surface of Wild Angelica (Angelica sylvestris). The leaf eventually breaks up (photo 3). Can anyone tell me what caused it, please?
Edit: Changed to match darob57's ID. Many thanks.