Allopatric populations of G. firmus and G. pennsylvanicus differ in overall body size and ovipositor length. A. Male pronotum width by species; B. Female pronotum width by species; C. Relative ovipositor length (ovipositor length/pronotum width). Boxplots indicate the mean values of each trait, quartiles, the range of the data (whiskers), and outliers. Individual data points are overlaid as scatterplots. Letters indicate the significant differences among groups (PWRST with corrected p-values < 0.05).