That's a thrips (Thysanoptera)! Nasty little creatures!
They feed on the plant's cell sap and pierce the surface of the leaves with their pronounced mouthparts.
It can help to spray the plant with a mild soap solution. Of course, depending on the growth stage.
In my opinion, the most effective way to get rid of these pests for good or at least keep them under control is nematodes. I would also set up yellow sticky traps 😁👍 wishing you lots of success in your battle!