Fig. 8. Functional model illustrating the suggested synergistic behaviour of the claws and tarsal tenent setae during vertical upward climbing on plants that combine attributes of both rough and smooth surfaces. (A) First, the claws cling to a surface irregularity; (B) because of the downward-directed pull of the leg, the ventral sides of the tarsomeres are subsequently pressed against the substratum, compressing the tarsal tenent setae. Note that this model assumes sub-apically recurved setae, but is also valid for smoothly curved setae.