Annotated checklist of the butterflies (Lepidoptera: Papilionoidea) of Burkina Faso, West Africa-synthesis and new occurrences.

Insect biodiversity documentation remains strikingly uneven, with significant knowledge gaps persisting for various taxa and regions. Butterflies (Papilionoidea), recognized as reliable bioindicators and flagship species, face such gaps in some West African countries, particularly Burkina Faso (BF). This study presents the most comprehensive and up-to-date checklist of butterflies in BF, compiling records from 29 diverse sources, including published literature, online databases, citizen science platforms and private collections. Our analysis reveals 220-225 butterfly species for BF, the presence of 5 of them being uncertain. This represents a 40% increase over previous compilations, including 47 new records for the country. We highlight pronounced disparities in research effort, with for instance Lycaenidae and Hesperiidae consistently underrepresented compared to Nymphalidae and Pieridae, probably because of sampling biases and intrinsic species ecological characteristics. Spatial analysis revealed limited and uneven geographic coverage, with vast areas, particularly northern BF, remaining largely unexplored. We discuss challenges related to data accessibility, taxonomic inconsistencies, and the impact of national security on biodiversity research. This synthesis not only significantly expands BF's known butterfly diversity but also underscores the deep need for building sustained and diversified research efforts, and local capacity to address remaining knowledge gaps in a country where entomological exploration still promises numerous discoveries.