Aptera (cockroach)

The term "aptera" (from Greek "a-" meaning "without" and "pteron" meaning "wing") was historically used in insect classification. In older taxonomic systems, Aptera referred to a subclass or order of insects considered to be primarily wingless throughout their adult lives. This group often included insects like silverfish, springtails, and bristletails.

However, modern entomology has largely abandoned the group Aptera as a valid taxonomic classification. This is because the winglessness in some of these insects is considered a primitive condition (they never evolved wings), while in others it is a secondary loss (their ancestors had wings but they were lost through evolution). Grouping insects solely on the absence of wings creates an artificial and inaccurate evolutionary picture.

Therefore, the insects previously classified as Aptera are now distributed among several different orders, reflecting a more accurate understanding of their evolutionary relationships. These include orders such as Thysanura (silverfish), Collembola (springtails), and Microcoryphia (bristletails).

The term "aptera" may still be encountered in older scientific literature, but it is crucial to understand that it does not represent a phylogenetically valid group in modern insect taxonomy. When referring to insects lacking wings, it is more accurate to refer to the specific orders to which they belong.