Parasitoid Wasp (IMAGE) University of Helsinki Caption Parasitoid wasps can be divided into two groups: idiobionts and koinobionts. Cryptus arcticus is an idiobiont attacking host larvae just as they are pupating. Since the host is already immobile at this stage, the parasitoid has to overwinter on site chosen by the host. Credit Tuomas Kankaanpää 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.