The relative leg length showed slightly different results (Fig. 3B). Here, we could distinguish a group comprising western specimens from Iberia (average relative leg length ± standard deviation = 1.35 ± 0.06) and Italy (1.37 ± 0.07), which were distinct from other populations by significantly shorter legs (anova, Games–Howell post hoc test, P < 0.05). Russian spiders and those from the two recently colonized locations shared a very similar relative leg length (average relative leg length Russia = 1.45 ± 0.06, Baltic = 1.45 ± 0.08, northeastern Germany = 1.45 ± 0.09). This analysis thus corroborated a closer relationship of Russian and expanding populations.