A Blacklegged Tick (IMAGE) Entomological Society of America Caption This is a blacklegged tick (Ixodes scapularis), the primary vector of Lyme disease. Credit Jim Gathany, CDC Usage Restrictions Credit Jim Gathany, CDC 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.