Mandibles of twenty species of short horned grasshoppers (Orthoptera: Caelifera) have variations among different species

Abstract

Mandibles are prominent masticatory structures in the mouth parts of grasshoppers provided an opportunity to analyze the structural variations among different species of grasshoppers. In this study structural variations in mandibles of twenty species of short horned grasshoppers are examined for two reasons - whether the grasshopper mandibles bear any taxonomic significance and to test if one could use mandible structures to establish inter species relationships among the grasshoppers. The morpho plan of mandibles having incisor, molar and basal regions remained consistent. The incisor region had variations in its teeth or denticles, the molar region had an architecture prominently represented in the form of ridges and grooves running along the length. The number of ridges and projections varied from species to species. The morphometric values of these regions showed variations between the species. The dendrogram constructed based on morphometric values followed three ways clustering. The molar structures in two species of Pyrgomorphidae exhibited different structures from that of Acrididae members. Adaptation of mandibles to the food habit and possible relationships among species of grasshoppers are discussed.