'American Idol' -- Bikini Girl ARRESTED for DUI

Katrina Darrell -- the chick who famously auditioned for "American Idol" in a bikini back in 2009 -- was arrested this morning for DUI ... TMZ has learned. According to Pomona PD Sgt. Patrick O'Malley, the 24-year-old singer ... also known as…

Jill Wagner Joanna Krupa Joanne Montanez Jodi Lyn OKeefe