Good god, you could see them?
Something tells me if you saw a few thrips, there are hundreds or worse.
I had one experience with thrips and beat them into submission with Orthene. Dilute as directed and direct spray application weekly for three consecutive weeks then once quarterly. It is a systemic and long lasting and the initial 3 week blasts will ensure you have nailed each life cycle and gotten them entirely eliminated.
Works great but 1 drawback is IT STINKS......wear mask, eye protection and gloves.