Phylogenetic patterns of leg morphometric traits in vespid wasps (Hymenoptera: Vespidae)

Vespid wasps use legs primarily for locomotion and in contexts such as grooming, handling of food and nest materials. Studies on leg form and function are relatively scarce. We analysed measurements of legs of 127 species of all genera of Polistinae, and of 18 species of other subfamilies, with the intent of investigating the occurrence and phylogenetic locations of morphometric patterns. Body‐size variation across Polistinae was determinant as to the absolute dimensions of legs, but allometric effects are generally small when comparing proportional length differences between differently sized species. Quite differently, size‐independent shape aspects are notably distinct as expressed by regression residuals and are clearly phylogenetically structured. Most distinctive are the very long mid and hind legs (and simultaneously exceedingly short forelegs) of Mischocyttarus species, and the comparatively shorter legs of some Epiponini. We found that forelegs have evolved with relative independence of the mid and hind legs, which is probably related to functions associated with the transport and manipulation of food and materials. Most examined solitary species showed mid and hindlegs shorter than most social polistines and vespines. Forefemur shape in some solitary species (euparagiines, masarines and some eumenines) may be functionally related to fossorial habits.