Formosan Subterranean Termite (IMAGE) University of Adelaide Caption Probably the most costly insect in the world is the Formosan subterranean termite (Coptotermes formosanus). Credit Image by Scott Bauer, US Department of Agriculture, Agricultural Research Service Usage Restrictions Only for use with this story. Please credit. 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.