Mandibular structure, gut contents analysis and feeding group of orthopteran species collected from different habitats of Satoyama area within Kanazawa City, Japan

In a survey of orthopteran assemblages from different habitats of Satoyama area, Kanazawa City, Ishikawa Prefecture, Japan, 50 different species belonging to 10 families representing 17 subfamilies and 27 tribes were recorded. Seven feeding groups were proposed based on stereo microscopic examination of mandibular morphology and analysis of gut contents. Among the examined subfamilies, family Tettigonidae proved to be the most diverse in term of mandible types, with four feeding groups. This was followed by family Acrididae, which also possessed a variety of mandibular structures with three feeding groups. Other families contained only single feeding groups. It was noted that only five species were graminivorous, all were from the family Acrididae, with mandibles characterized by very short incisors and relatively wide molar regions. The gut contents of these five species contained more than 80% monocotyledonous plant species