Board Thread:Episodic and Issue Discussion/@comment-47881-20130118212340/@comment-5008987-20130119231236

Did Brandon Vietti and Greg Weisman really created Green Beetle? Impulse said that He "did not appear in any history books". .......

When Impulse mentioned that he wasn't found in any history books, he meant that he had never read/heard of, or seen, the Green Beetle before (in the future). This, is in no way, references whether Green Beetle is an original character or not, created by Brandon and Greg (as a post to being a canon made by some other person in the past). As for your question, as far as I'm aware, he is an original character that could have either been created by them, or some other employees that work on Young Justice.