Fig. 6. Comparisons of pulling forces per single tenent seta between claw-amputated
beetles of three Stenus species on various test surfaces (arithmetic
means ± S.D.). Values of N are given below the
x-axes. During maximum pulling performance, all six tarsi usually
have contact with the test surface, so the maximum pulling forces were divided
by the total number of tenent setae on all six tarsi. The latter was
approximated by multiplying the number of tenent setae counted on the hind
tarsi (see table 1 in
Betz, 2002) by six. S.
pubescens and S. cicindeloides are species with wide tarsi,
whereas S. comma has slender tarsi. S. cicindeloides was
tested on only three of the five surfaces. The letters above the error bars
indicate statistically significant interspecific differences (Mann-Whitney
U-test; P<0.05).
