Picture of a Dragonfly (IMAGE) Penn State Caption Penn State researchers studied the dragonfly, Libellula pulchella, and discovered that a supposedly harmless parasite triggers metabolic disorders similar to those found in humans afflicted with insulin resistance, type 2 diabetes and obesity. Credit None Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.