How to prevent (further) damage
We always recommend biological control. To get rid of thrips this way, you can make use of the predatory bug Orius. You can buy these natural predators of thrips online and in most garden centres. Adult Orius tuck into any stage of thrips, while the nymphs prefer the larvae. Orius also take care of other insects like aphids, mites and whiteflies. You can also use a non-toxic foliar spray such as Crop Guard - LaminAid TH
which is used to create an electrostatic charge on the surface of the plant, zapping anyway anything in contact.
Thrips are small, slender insects with fringed wings. They are greyish to brown in colour and at most a single millimetre long. The females lay their eggs in the plant’s tissue. They make an opening in the tissue in which they lay their kidney-shaped eggs. The larvae start eating as soon as they have hatched.