Oh, my ... I am so sorry for you and your plants! The damage looks like they might be flea beetles. They are very small about 1/16th of an inch long (although the insects in your photos appear to be larger) and jump when disturbed. Most are shiny black, but some have an metallic bluish or greenish appearance. There are many different kinds. This is a link providing information about canola crops, but it shows the characteristic damage they do.