Table 2.

Maximum vertical pulling forces achieved by representatives of 18 Stenus and one Dianous species on various substrata

Vertical pulling forces on various surfaces (mN) (force/weight ratios are given in parentheses)
SpeciesNBody mass (mg)GlassPhotographic paperDry Phragmites leavesFilter paper
sg. Stenus s. str.
S. biguttatus L.101.977±0.200.047±0.02a0.100±0.05b1.135±0.27c1.931±0.42d
(2.4)(5.3)(58.5)(101.0)
S. bimaculatus Gyllenhal104.916±0.710.050±0.01a0.52±0.04a0.846±0.50b2.241±0.55c
(1.1)(1.2)(18.2)(45.9)
S. comma Leconte102.617±0.310.092±0.06a0.106±0.04a0.949±0.19b1.823±0.25c
(3.8)(4.2)(36.5)(72.9)
S. fossulatus Erichson101.926±0.290.145±0.08a0.120±0.05a0.750±0.20b1.536±0.29c
(7.7)(6.5)(40.7)(83.6)
S. juno Paykull103.537±0.560.047±0.02a0.037±0.02a0.523±0.36b1.898±0.49c
(1.4)(1.1)(15.7)(56.6)
S. providus Erichson32.439±0.160.081±0.060.055±0.030.381±0.111.511±1.02
(3.3)(2.3)(15.8)(62.1)
sg. Nestus
S. boops Ljungh101.238±0.150.123±0.05a0.066±0.04b0.916±0.18c2.165±0.56d
(10.0)(5.6)(75.8)(177.3)
S. canaliculatus Gyllenhal101.024±0.150.099±0.06a0.076±0.05a0.568±0.14b1.795±0.29c
(10.3)(8.3)(57.8)(178.5)
sg. Hypostenus
S. cicindeloides Schaller103.464±0.251.370±0.24a0.179±0.11b1.871±0.23c2.941±0.46d
(41.0)(5.2)(54.9)(85.6)
S. similis Herbst102.942±0.270.970±0.28a0.424±0.22b0.875±0.18a2.321±0.28c
(33.5)(14.7)(31.3)(79.9)
S. solutus Erichson102.782±0.251.551±0.33a0.596±0.25b1.419±0.51a2.756±0.70c
(57.5)(22.6)(51.7)(102.5)
S. latifrons Erichson100.938±0.100.455±0.11a0.173±0.11b0.507±0.16a1.477±0.41c
(50.2)(18.8)(55.2)(159.8)
S. tarsalis Ljungh101.592±0.161.223±0.14a0.400±0.14b1.269±0.45a2.195±0.36c
(80.8)(26.7)(78.2)(139.3)
sg. Metastenus
S. bifoveolatus Gyllenhal101.370±0.121.267±0.35a0.214±0.13b1.202±0.22a3.015±0.76c
(94.5)(16.0)(93.3)(220.7)
S. binotatus Ljungh102.060±0.190.959±0.30a0.697±0.38a1.539±0.41b2.622±0.97c
(49.5)(34.4)(75.7)(129.2)
S. nitidiusculus Stephens102.196±0.181.355±0.19a0.173±0.11b1.648±0.29c3.253±0.72d
(64.0)(8.3)(76.9)(149.3)
S. pubescens Stephens123.958±0.291.458±0.38a0.617±0.26b1.738±0.41c2.671±0.38d
(38.7)(16.4)(44.7)(66.7)
sg. Hemistenus
S. impressus Germar101.461±0.200.373±0.17a0.093±0.05b0.838±0.31c1.297±0.35d
(25.5)(6.4)(62.6)(90.6)
g. Dianous
D. coerulescens Gyllenhal103.899±0.440.169±0.09a0.120±0.04a1.635±0.26b2.856±0.35c
(4.6)(3.1)(43.1)(75.0)
  • Values are arithmetic means ± S.D.

    Different letters refer to statistically significant intraspecific differences at the 5 % level (Friedman test, Wilcoxon test).

    For S. providus, no statistical comparisons were performed because the sample size was too low.

    For comparative purposes, the ratio of pulling force to body weight is added in parentheses.

    The number of tarsal tenent setae for each species is listed in Table 1 of Betz (2002). The assignment of the species to subgenera follows Herman (2001). g, genus; sg, subgenus.