Hello,
Is this an Outdoor grow? Honestly it looks to be bug or worm poop and removing them by spraying and It showing up very next morning supports that. But it is hard to give a good diagnoses off a picture. It also looks like you might have some bud damage just to the left of the white spots? See if you can dig around and find a worm or any other type of pest around there. Do you see any little black dots that can be removed with a finger nail? Now it does appear you are pretty close to harvest so spraying might be out of the question at this point. They do sell sprays such as Nukem That you can spray up to harvest but me being me I am not a fan of doing that. On the bright side its not mold/fungus or anything like that. PM me if you have follow up questions. Have a good one.