Anyone Know What These Bugs Are?

I've seen thousands of these bugs this year. I live in the Eastern plains of Colorado near Denver.  The bugs are approx 3/16" in length.  They are covering my black locust seedlings, all over my corn and Jerusalem artichokes. My black locust seedlings are really spindly and have leaves that are curled. The bugs are either causing this or the trees have some sort of disease that is attracting these bugs. I'm sure they are common bugs, but I've never seen as many as we have this year. I've searched all over the internet and haven't figured out what they are. Anyone know what they are or have recommendations on how to safely control them? I appreciate your help, thanks!

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