Tortoise Beetle (image) Emory Health Sciences Share Print E-Mail Caption The tortoise beetle, which eats thistle leaves, has evolved a symbiotic relationship with bacteria that allows it to have such a specialized diet. Credit Photo by Hassan Salem. Usage Restrictions Must include credit. Share Print E-Mail 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.