Hypolimnas Bolina Female (IMAGE) University of California - Berkeley Caption Shown is a female Hypolimnas bolina, also called the Blue Moon or Great Eggfly butterfly. The proportion of females in some populations of H. bolina in the South Pacific reached 99 percent as a result of infection by a bacteria that kills males before they hatch. However, researchers recently witnessed a remarkable comeback of male butterflies on some islands thanks to the rise of a suppressor gene. Credit Sylvain Charlat 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.