Modern techniques in molecular biology use gene sequences to identify bacteria and provide a means of comparing the numbers and similarity. Scientists from Colorado and Panama* compared the gut bacteria in larvae and adults of a tropical butterfly, Heliconius erato. They found that the composition of the bacteria was different. The larvae had greater diversity of bacteria than adults. Less than 13% of the bacteria species were found in both adult and larvae. The contribution that bacteria are making to larvae and adults of this butterfly and most Lepidoptera are unknown. Contributions from bacteria may enable a caterpillar to grow better on certain hosts. Modern techniques have made gut bacteria a fertile area for research.
*Hammer TJ, McMillan WO, Fierer N (2014) Metamorphosis of a Butterfly-Associated Bacterial Community. PLoS ONE 9(1): e86995.