Table 4.

Adhesion and adhesive stress for all pads of male and female beetles (data corresponding to friction values presented in Table 3)

Male Female
AdhesionPad:DistalMiddleProximalDistalMiddleProximal
Smooth surfacePullForce (mN)2.25±0.660.52±0.144.24±0.341.30±0.310.29±0.101.01±0.34
(N=5)Stress (kPa)100±2768±18142±1153±1053±2155±18
PushForce (mN)0.22±0.070.30±0.130.37±0.190.19±0.070.14±0.070.14±0.06
(N=5)Stress (kPa)33±1247±2027±919±557±1832±12
Rough surfacePullForce (mN)0.49±0.170.14±0.040.13±0.020.69±0.100.09±0.030.12±0.04
(N=5)Stress (kPa)20±718±54±126±411±36±2
PushForce (mN)0.13±0.020.11±0.030.11±0.030.10±0.030.10±0.030.09±0.04
(N=5)Stress (kPa)8±126±65±16±127±811±4
  • Values are mean ± s.e.m. Again, for the rough surface, area was estimated using the mean maximal setal contact area on glass