Calypter

The calypters are small membranous flaps or lobes that are located at the base of the wing in some species of fly (Order Diptera). Flies often have two calypters (commonly called the upper and lower calypters) on either side of their bodies. The presence of calypters is an important diagnostic feature and is often used by entomologists to help identify different species of fly.

The calypters often look like small round wings. As a result, many people mistake the calypters for a fly's halteres. This is because the halteres are often described as "modified hind wings" and so people assume these small wing-like structures are the halteres. The halteres are actually shaped like a drum-stick and can be hidden below the calypter. If the halteres are hidden by the calypter then the calypter can also be called an alula.

A photograph of the blowfly Lucilia sericata showing the calypters.
Photograph by Alvesgaspar licensed under Creative Commons.

Other names for (or types of) Calypter include:

• Alula
• Squama
• Squamula
• Tegula

Related terms

• Acalyptrate
• Alary
• Diptera
• Discal cell
• Haltere
• Thorax

Related groups of terms

• Invertebrate body structure

Related pages on this web site

• True flies - Order Diptera

See other words beginning with C