Plant diets of Gryllus bimaculatus and Locusta migratoria revealed by trnL metabarcoding

Edible orthopterans represent promising sustainable protein sources, yet their natural plant diets remain poorly characterized, limiting optimized feed development in farms. Here we applied chloroplast trn L metabarcoding to gut contents of Gryllus bimaculatus and Locusta migratoria sampled in Iberian field sites to provide a descriptive account of the plants ingested by two economically relevant species. Results revealed that L. migratoria 's diet is dominated by Poaceae grasses and Asteraceae forbs, notably Dactylis, Cynodon, Sorghum, Bromus and Tragopogon dubius . In contrast, G. bimaculatus displayed a richer plant diversity, dominated by Asteraceae and Poaceae with contributions from Malvaceae and Amaranthaceae; including Oxytropis campestris, Cynodon dactylon and Dactylis glomerata . These findings document the plant fraction of their diets (as trn L targets chloroplast DNA), complementing previous omnivory reports, and identify candidate taxa for palatability testing and feed formulation. Additionally, detection of potentially toxic plants (e.g. Oxytropis, Mercurialis ) suggests the need for safety evaluations. Overall, this study provides actionable insights into orthopteran foraging ecology to inform sustainable insect farming practices.