I recently noticed a few very tiny little green specks on one of my new dahlia blooms. I didn't think much of it. They almost looked like dirt or pollen they are so tiny. I recently placed my potted plants into a new small starter green house I just built. Upon inspecting them this morning, I see a lot more of these tiny green specs on my newly opening dahlia buds. I am assuming these are some kind of bug. I removed that plant from the greenhouse and sprayed it with a strong stream of water. I noticed only one other dahlia plant in there has a few brown tiny specks on it. I removed that plant as well. What are these tiny bugs and how do I get rid of them?