Zygentoma (Smith and Watson, 1991)

R. G. Beutel & S. N. Gorb, 2001, Ultrastructure of attachment specializations of hexapods (Arthropoda): evolutionary patterns inferred from a revised ordinal phylogeny, J. Zool. Syst. Evol. Research 39, pp. 177-207 : 179

5 Zygentoma

The tarsus is three­segmented in most members of Zygentoma ( Smith and Watson 1991) but five­segmented in Tricholepidion gertschi Wygodzinsky 1961 ( Wygodzinsky 1961: Figs 29, 30). The reduced pretarsus bears one median empodial claw and a pair of lateral claws ( Fig. 4A ).

Figures

Fig. 4. Details of hexapod tarsi and pretarsi. (A) Lepisma saccharina (Zygentoma), foreleg, pretarsus, lateral aspect. (B) Paraleptophlebia sp. (Ephemeroptera), midleg, pretarsus, ventral aspect. (C) Blatella germanica (Blattodea), midleg, tarsus, ventro­lateral aspect. (D) Omocestus viridulus (Caelifera), foreleg, tarsus, ventral aspect. (E) Cercopis vulnerata (Auchenorrhyncha), midleg, pretarsus, ventro­lateral aspect. (F) Chrysoperla carnea (Neuroptera), pretarsus, ventral aspect. (G, H) Schistocerca gregaria (Caelifera), foreleg, arolium sagittal section, triple stain after Cason. (I) Brachyptera risi (Plecoptera), midleg, arolium, sagittal section, triple stain after Cason. (J) Cercopis vulnerata (Auchenorrhyncha), midleg, sagittal section, triple stain after Cason. Black arrows indicate ventral directions. AR, arolium; CP, claw pad; EU, euplantulae; RD, chitinous threads; TAR, tarsal segments; TI, tibia; UN, claw, UN1, ephemeropteran hook­like claw, UN2, ephemeropteran pad­bearing claw