Calypter is a term that refers to the small, often scale-like structure that covers the base of a fly's wing. While not a widely known term, there are several synonyms that can be used to describe this structure. Colloquially known as the squama, it can also be referred to as the wing cover, alula, or tegula. Each of these terms describes a different aspect of the structure, from its protective function to its role in flight control. While the word "calypter" may be specific to flies, these synonyms offer a broader understanding of the important structures on insects' wings.