Which cartoonist tried to sell to a national comic strip syndicate,one of his creation, but was told, "It's funny. But bugs? Who can relate to a bug?"

That would be Jim Davis (creator of Garfield) and the cartoon in reference is "Gnorm Gnat" which ran in an Indiana newspaper I believe.

I like how this one ended!

From this website:

"After five years of drawing Gnorm, Davis drew a giant foot that fell out of the sky, crushing Gnorm in his last comic appearance."

Good answers, thanx both of you.