Body size, sexual dimorphism and ecological succession in grasshoppers

Abstract

We studied 12 species of Acrididae (4 Oedipodinae and 8 Gomphocerinae) associated with three ecological stages of succession in herbaceous environments in mine tailings near Limoges, France. The pioneer, medium and late stages of succession each contained four different dominant grasshopper species. We measured morphometry variables possibly linked with displacement (locomotory) capacities, taking advantage of previous analyses on walking and jumping-flight performances on the same species.Early succession species were characterized by long hind and fore wings and a wider pronotum. Their wings also exhibited greater sexual dimorphism in length than grasshopper species from middle or late successional stages. These morphological characters are associated with jumping-flight performances and walking speed, because the best jumpers are the best walkers. Although the ratio of wing length to body length decreases with succession, the overall body size does not, and overall body size is not correlated with displacement performance.