Sexual dimorphism and the exaggerated traits are the results of sexual selection, mate choice and/or male-male competition. Recent studies show that exaggerated trait is supported by other traits (i.e. supportive traits) and they also influence the outcome of competition. By examining allomerties of exaggerated and other traits and thus comparing these between sexes, we can know what traits are related to the composition of exaggerated trait and are influenced on sexual selection.

Sagra femorata male has larger hind legs rather than female. Recently we found that the male exaggerated hind legs are used in male-male combat during mating, in the way that the intruder tear mating male off from the pairing female. However, it is unclear how the sizes of hind legs, as well as supportive legs, affect on male-male combat and mating.

First, we assessed the allometric relationship between body size and the size of fore-, mid- and hind-legs of both sexes. Then, we examined whether each male leg size affects male-male combat and mating outcomes. From our results, we discuss the function of exaggerated and supportive traits on mating and combat in Sagra femorata .