Can you tell the age of a wasp by the size of its abdomen?

No, you can not determine a wasp's age by the size of its abdomen. Unlike some other insects, such as butterflies, wasps do not have a specific and identifiable growth stage where they stop molting and their body size remains constant. During their life cycle, they undergo multiple metamorphoses from egg to larvae to adult, and they continue to grow and molt through their lives.

Therefore, the size of a wasp's abdomen can vary depending on many other factors such as its sex, species, diet, and the availability of resources. For instance, a female wasp that has just emerged from its cocoon might have a smaller abdomen than a male that is about to mate. Similarly, a wasp that has fed on a high-protein diet might have a larger abdomen than one that has been deprived of nutrients.

In summary, although a wasp's abdomen size can provide clues about its sex, species, and physiological state, it is not a reliable indicator of its age.