I found these little beetles on a weed top in my garden today. There were many clustered eating the tender tips. They were not moving very fast - even when disturbed. They are a metallic brown with a hint of green to them, and indentations in a row down their sides. I am curious if they are bad for my garden - or should I leave them be. I have left them alone so far because they are just devouring a weed and a daisy right now. We noticed them in the sun - afternoon time. Any help would be great thanks!