Infected Larvae (IMAGE) Max Planck Institute for Chemical Ecology Caption Larva (above and middle) and pupa (below) of the cotton leafworm Spodoptera littoralis; both have been infected with pathogenic Enterococcus faecalis bacteria. Enterococcus mundtii symbionts in the gut of healthy caterpillars kill these pathogens and inhibit infection. Credit Yongqi Shao, Zhejiang University, Hangzhou, China 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.