Figure 7. Comparisons of the traction force data obtained on tethered beetles walking between two plates with a rough lower substrate (a) and a smooth lower substrate (b).

In both diagrams the forces are sorted by the manipulation status, which is indicated by the drawings of the beetle legs: intact, removed spurs, removed claws, and both structures removed. On the rough surface, we tested ten intact beetles, ten beetles with removed spurs, ten with removed claws, and nine with both spurs and claws removed. On the smooth surface, ten intact beetles were tested, six with removed spurs, seven with removed claws, and four with both types of structures removed. With each beetle we performed five runs.