Comparison of Microhabitats of Three Grasshopper Species and Their Jumping Performance on Solid and Non-solid Substrates

Abstract

Acrida cinerea, Atractomorpha lata and Oedaleus infernalis are common grasshopper species in Korea and East Asia regions. However, habitats and microhabitat differences between these grasshopper species are not well documented. Microhabitats can be divided between grasshoppers involving locomotion (jumping) on solid substrates (ground) and on non-solid substrates such like stems of plants. Adaptations to jump from these two different types of substrates have not been empirically studied. Here, I studied the use of plants by the three grasshopper species and found clear differences between the three species. By using high-speed camera, I measured jumping performances (body speed, jumping latency, jumping efficiency) of these three grasshopper species on six artificial substrates imitating natural solid and non-solid substrates. Finally, I compared locomotor elements of motor pattern related to the specifics of jumping mechanism (maximum angle 1 speed, departure angle 6, departure angle 8, initial angle 8, substrate shift, mass ratio) between the different substrates for each of the three species. Results revealed that, regardless of the substrate, male Oedaleus infernalis, the species with best developed jumping muscles, had best jumping performance. Jumping performance related to escaping from predators (body speed, jumping latency) depended on the maximum angle 1 speed while the other jumping performance (jumping efficiency) depended on the departure angle 6 and substrate shift. Species with distinctly different anatomy, Acrida cinerea, differed in some aspects of jumping from the remaining two species. Further research connecting morphological traits, like hind leg length and muscle area, with jumping mechanism is needed to reveal how morphology changes depending on the microhabitat-specific selective pressures.