Although Gryllus bimaculatus is widely used as a laboratory model organism, its ecology under natural conditions remains poorly understood. Here, we provide a preliminary assessment of the field diet and trophic ecology of wild G. bimaculatus using stable isotope analysis and gut-content DNA metabarcoding. Stable isotope analysis provided a preliminary estimate of the trophic position of G. bimaculatus, suggesting that it occupies an intermediate position between herbivores and carnivores. In contrast, gut-content DNA metabarcoding detected animal-derived material only rarely, while revealing a broad range of plant species. Plant-derived dietary taxa were dominated by Poaceae and Fabaceae. This apparent discrepancy may indicate that G. bimaculatus primarily relies on plant-derived resources, while consuming animal-derived material, such as insect carcasses, opportunistically when it becomes available. These findings provide baseline information on the natural diet of G. bimaculatus and may contribute to the development of laboratory diets that more closely reflect the species' natural nutritional resources, potentially improving the nutritional optimization of mass-rearing systems.