Apterygota

…Insects are divided into two groups based on the presence or absence of wings, which is a major characteristic of insects. The Apterygota subclass is a group that has never had wings, and among them, the Thymidia are considered to be closely related to the ancestors of the Pterygota. However, some researchers consider each order of the Apterygota to be an equal taxonomic group to the Pterygota, or to be an independent group from insects, and some consider the Collembola order, which has a particularly large number of species and individuals, to be a rather special class. …

*Some of the terminology explanations that mention "Apterygota" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…昆虫はその大きな特徴である翅の存否によって，まず二大別される。無翅亜綱Apterygotaは今まで翅を出現させたことがなかった類で，このうちシミ目が有翅亜綱の祖先型に近縁とされる。ただし研究者によっては，無翅亜綱の各目は，有翅亜綱と対等の分類群，もしくは昆虫とは独立な群とみなされ，ことに種数，個体数ともに多いトビムシ目は，かなり特殊な別の類だとの見解がある。…

※「Apterygota」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報