Interspecific effects of body size on grasshopper jumping performance

Abstract

The scaling of jump performance has been relatively well studied in vertebrates; however, less is known about how interspecific body size differences affect insect jumping. In this study, we compare the morphology, jump performance, lactate production, and relative cost of drag in sixteen species of grasshoppers using both standard regression and phylogenetic generalized least squares analyses. In contrast to the situation observed across species in vertebrates, and during ontogeny in Schistocerca americana grasshoppers, small grasshopper species had similar jump distances as larger species, despite losing more energy to drag. This surprising result could be at least partially explained by the fact that smaller grasshopper species had relatively more jumping muscle mass, relatively longer femurs, and produced more lactate during repeated jumping. These data suggest that selection has acted strongly to improve jump performance in smaller grasshoppers via a variety of morphological and biochemical adaptations.