Four chapters about the monophyly of insect ‘orders’: A review of recent phylogenetic contributions
Recent phylogenetic analyses, both morphological and molecular, strongly support the monophyly of most insect ‘orders’. On the contrary, the Blattaria, Psocoptera, and Mecoptera are definitely paraphyletic (with respect of the Isoptera, Phthiraptera, and Siphonaptera, respectively), and the Phthiraptera are possibly diphyletic. Small relictual subclades that are closely related to the Isoptera, Phthiraptera, and Siphonaptera were identified (Cryptocercidae, Liposcelididae, and Boreidae, respectively), which provides an enormous amount of evidence about the origin and early evolution of the highly apomorphic eusocial or parasitic ex-groups. Position of the enigmatic ‘zygentoman’ Tricholepidion Wygodzinsky, 1961, remains uncertain. Possible non-monophyly of the Megaloptera (with respect of the Raphidioptera) and the Phasmatodea (with respect of the Embioptera) are shortly discussed.