Does anyone know what this is? Is it harmful?
Looks like spider mites. Mix 1 part 70% isopropyl alcohol to 3 parts water in a spray bottle and spray the plant once or twice a day. Make sure you get the underside of the leaves. The alcohol is a contact killer so it will probably take a few days to get rid of them. Give the plant a quick rinse with plain water before harvest. This is the method for herbs and vegetables. I don't know if there are any differences for your particular plant.
