First DNA barcode reference library of grasshoppers on the Comoros Archipelago

DNA barcoding studies utilising COI gene sequences have been widely applied in insect taxonomy for two decades and remain so. Barcode reference libraries are a valuable molecular resource for future biodiversity assessments, including standard barcoding surveys and environmental DNA (eDNA) approaches. Grasshoppers, members of the suborder Caelifera of the insect order Orthoptera, on the Comoros Islands have not yet been subject of barcoding studies, marking a clear gap in a poorly-studied region of high biodiversity and endemism. Our results illustrate both the potential and the constraints of CO1 barcodes in caeliferan systematics and highlight the importance of expanding molecular reference libraries in understudied biodiversity hotspots.

We provide a first barcode reference library, including COI sequences from 22 Caelifera specimens representing 12 genera and 15 species. Nine out of 12 genera can be reliably identified using DNA barcodes. However, closely-related taxa, such as Symbellia species, were not well resolved by CO1 alone, highlighting the need for additional markers and morphological evidence. Furthermore, preliminary evidence suggests the presence of different Parepistaurus lineages on the Archipelago, potentially indicating undescribed diversity and deserving further study.