Comparison of body size of B. lapidarius workers in the various sampling regions.
Body size of workers significantly differed in the three regions, namely Schwäbische Alb (ALB), Hainich-Dün (HAI), and Schorfheide-Chorin (SCH) (LMM: χ2 = 6.682, N = 307, p < 0.05). Boxplots show the median range, interquartile range, and the minimum and maximum ranges. Outliers are shown as individual dots. Different capital letters indicate significant differences among groups.