Sternorrhyncha

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 : 180

22 Sternorrhyncha

The tarsus is two­segmented in most representatives of Sternorrhyncha , but one­segmented in coccoids ( Strumpel 1983). A cushion­like, simple or bilobed arolium is present in many psylloids. Some representatives of Aphididae possess pulvilli. Other aphidid species examined are characterized by an eversible structure resembling euplantula between tibia and tarsus ( Lees and Hardie 1988; Dixon et al. 1990) ( Fig. 3f ).

Figures

Fig. 3. Diversity of the leg attachment devices (gray­colored areas) in hexapods. (a) Arolium (smooth). (b) Pulvilli (smooth or hairy). (c) Empodial pulvillus (ep) (hairy). (d) Hairy adhesive soles of tarsomeres. (e) Eversible pretarsal bladder (smooth). (f) Eversible structure between tibia and tarsus (smooth). (g) Fossula spongiosa (hairy). (h) Euplantulae (eu) and claw pad (cp) (both smooth). (i) Tarsal thorns transformed into adhesive structures (th), claw pad (cp) (both smooth). (j) Adhesive claw setae