For the first time ever, a team led by the University of Colorado Boulder has sequenced the internal bacterial makeup of the three major life stages of a butterfly species, a project that showed some surprising events occur during metamorphosis.
The team, led by CU-Boulder doctoral student Tobin Hammer, used powerful DNA sequencing methods to characterize bacterial communities inhabiting caterpillars, pupae and adults of Heliconius erato, commonly known as the red postman butterfly. The red postman is an abundant tropical butterfly found in Central and South America.
The results showed the internal bacterial diversity of the red postman was halved when it morphed from the caterpillar to the chrysalis, or pupal stage, then doubled after the pupae turned into active adult butterflies. The study is important because communities of bacteria inhabiting other insects have been shown to affect host nutrition, digestion, detoxification and defense from predators, parasites and pathogens, said Hammer of the ecology and evolutionary biology department.