Entognatha

known for a common body structure consisting of the famous three pairs of legs, abdomen, thorax and head, is divided into two taxonomic groups: the Entognatha and the Ectognatha (Sasaki et al., 2013). Within the Entognatha are the orders Diplura, Collembola, and Protura (Sasaki et al., 2013). These are all wingless orders (Sasaki et al., 2013). The Entognatha are marked by an entognathy, which is seen as their mouthparts being further inside their head, being enclosed by extensions of the head (Reiger